Early College Entrance: How Will My Child Do?

ERIC Educational Resources Information Center

Chung, Rachel U.; Hertzog, Nancy B.

2014-01-01

Early college entrance is a form of acceleration, or the process of advancing students in academic programs faster than their same-aged peers. Many early entrants have demonstrated academic ability to achieve at high levels but they exhibit tremendous variety in their age, specific abilities, social and emotional maturity, family support, and…

Genome-wide association study (GWAS) for growth rate and age at sexual maturation in Atlantic salmon (Salmo salar).

PubMed

Gutierrez, Alejandro P; Yáñez, José M; Fukui, Steve; Swift, Bruce; Davidson, William S

2015-01-01

Early sexual maturation is considered a serious drawback for Atlantic salmon aquaculture as it retards growth, increases production times and affects flesh quality. Although both growth and sexual maturation are thought to be complex processes controlled by several genetic and environmental factors, selection for these traits has been continuously accomplished since the beginning of Atlantic salmon selective breeding programs. In this genome-wide association study (GWAS) we used a 6.5K single-nucleotide polymorphism (SNP) array to genotype ∼ 480 individuals from the Cermaq Canada broodstock program and search for SNPs associated with growth and age at sexual maturation. Using a mixed model approach we identified markers showing a significant association with growth, grilsing (early sexual maturation) and late sexual maturation. The most significant associations were found for grilsing, with markers located in Ssa10, Ssa02, Ssa13, Ssa25 and Ssa12, and for late maturation with markers located in Ssa28, Ssa01 and Ssa21. A lower level of association was detected with growth on Ssa13. Candidate genes, which were linked to these genetic markers, were identified and some of them show a direct relationship with developmental processes, especially for those in association with sexual maturation. However, the relatively low power to detect genetic markers associated with growth (days to 5 kg) in this GWAS indicates the need to use a higher density SNP array in order to overcome the low levels of linkage disequilibrium observed in Atlantic salmon before the information can be incorporated into a selective breeding program.

Intracellular Transport of Vaccinia Virus in HeLa Cells Requires WASH-VPEF/FAM21-Retromer Complexes and Recycling Molecules Rab11 and Rab22

PubMed Central

Hsiao, Jye-Chian; Chu, Li-Wei; Lo, Yung-Tsun; Lee, Sue-Ping; Chen, Tzu-Jung; Huang, Cheng-Yen

2015-01-01

ABSTRACT Vaccinia virus, the prototype of the Orthopoxvirus genus in the family Poxviridae, infects a wide range of cell lines and animals. Vaccinia mature virus particles of the WR strain reportedly enter HeLa cells through fluid-phase endocytosis. However, the intracellular trafficking process of the vaccinia mature virus between cellular uptake and membrane fusion remains unknown. We used live imaging of single virus particles with a combination of various cellular vesicle markers, to track fluorescent vaccinia mature virus particle movement in cells. Furthermore, we performed functional interference assays to perturb distinct vesicle trafficking processes in order to delineate the specific route undertaken by vaccinia mature virus prior to membrane fusion and virus core uncoating in cells. Our results showed that vaccinia virus traffics to early endosomes, where recycling endosome markers Rab11 and Rab22 are recruited to participate in subsequent virus trafficking prior to virus core uncoating in the cytoplasm. Furthermore, we identified WASH-VPEF/FAM21-retromer complexes that mediate endosome fission and sorting of virus-containing vesicles prior to virus core uncoating in the cytoplasm. IMPORTANCE Vaccinia mature virions of the WR strain enter HeLa cells through fluid phase endocytosis. We previously demonstrated that virus-containing vesicles are internalized into phosphatidylinositol 3-phosphate positive macropinosomes, which are then fused with Rab5-positive early endosomes. However, the subsequent process of sorting the virion-containing vesicles prior to membrane fusion remains unclear. We dissected the intracellular trafficking pathway of vaccinia mature virions in cells up to virus core uncoating in cytoplasm. We show that vaccinia mature virions first travel to early endosomes. Subsequent trafficking events require the important endosome-tethered protein VPEF/FAM21, which recruits WASH and retromer protein complexes to the endosome. There, the complex executes endosomal membrane fission and cargo sorting to the Rab11-positive and Rab22-positive recycling pathway, resulting in membrane fusion and virus core uncoating in the cytoplasm. PMID:26041286

Binocular pattern deprivation interferes with the expression of proteins involved in primary visual cortex maturation in the cat.

PubMed

Laskowska-Macios, Karolina; Nys, Julie; Hu, Tjing-Tjing; Zapasnik, Monika; Van der Perren, Anke; Kossut, Malgorzata; Burnat, Kalina; Arckens, Lutgarde

2015-08-14

Binocular pattern deprivation from eye opening (early BD) delays the maturation of the primary visual cortex. This delay is more pronounced for the peripheral than the central visual field representation within area 17, particularly between the age of 2 and 4 months [Laskowska-Macios, Cereb Cortex, 2014]. In this study, we probed for related dynamic changes in the cortical proteome. We introduced age, cortical region and BD as principal variables in a 2-D DIGE screen of area 17. In this way we explored the potential of BD-related protein expression changes between central and peripheral area 17 of 2- and 4-month-old BD (2BD, 4BD) kittens as a valid parameter towards the identification of brain maturation-related molecular processes. Consistent with the maturation delay, distinct developmental protein expression changes observed for normal kittens were postponed by BD, especially in the peripheral region. These BD-induced proteomic changes suggest a negative regulation of neurite outgrowth, synaptic transmission and clathrin-mediated endocytosis, thereby implicating these processes in normal experience-induced visual cortex maturation. Verification of the expression of proteins from each of the biological processes via Western analysis disclosed that some of the transient proteomic changes correlate to the distinct behavioral outcome in adult life, depending on timing and duration of the BD period [Neuroscience 2013;255:99-109]. Taken together, the plasticity potential to recover from BD, in relation to ensuing restoration of normal visual input, appears to rely on specific protein expression changes and cellular processes induced by the loss of pattern vision in early life.

[Thyroid hormones and the development of the nervous system].

PubMed

Mussa, G C; Zaffaroni, M; Mussa, F

1990-09-01

The growth and differentiation of the central nervous system are closely related to the presence of iodine and thyroid hormones. During the first trimester of human pregnancy the development of the nervous system depends entirely on the availability of iodine; after 12 week of pregnancy it depends on the initial secretion of iodothyronine by the fetal thyroid gland. During the early stages of the development of the nervous system a thyroid hormone deficit may provoke alterations in the maturation of both noble nervous cells (cortical pyramidal cells, Purkinje cells) and glial cells. Hypothyroidism may lead to cellular hypoplasia and reduced dendritic ramification, gemmules and interneuronal connections. Experimental studies in hypothyroid rats have also shown alterations in the content and organization of neuronal intracytoplasmatic microtubules, the biochemical maturation of synaptosomes and the maturation of nuclear and cytoplasmatic T3 receptors. Excess thyroid hormones during the early stages of development may also cause permanent damage to the central nervous system. Hyperthyroidism may initially induce an acceleration of the maturation processes, including the migration and differentiation of cells, the extension of the dendritic processes and synaptogenesis. An excess of thyroid hormones therefore causes neuronal proliferation to end precociously leading to a reduction of the total number of gemmules. Experimental research and clinical studies have partially clarified the correlation between the maturation of the nervous system and thyroid function during the early stages of development; both a deficit and excess of thyroid hormones may lead to permanent anatomo-functional damage to the central nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)

Viewing pre-60S maturation at a minute’s timescale

PubMed Central

Zisser, Gertrude; Ohmayer, Uli; Mauerhofer, Christina; Mitterer, Valentin; Klein, Isabella; Rechberger, Gerald N; Wolinski, Heimo; Prattes, Michael; Pertschy, Brigitte; Milkereit, Philipp

2018-01-01

Abstract The formation of ribosomal subunits is a highly dynamic process that is initiated in the nucleus and involves more than 200 trans-acting factors, some of which accompany the pre-ribosomes into the cytoplasm and have to be recycled into the nucleus. The inhibitor diazaborine prevents cytoplasmic release and recycling of shuttling pre-60S maturation factors by inhibiting the AAA-ATPase Drg1. The failure to recycle these proteins results in their depletion in the nucleolus and halts the pathway at an early maturation step. Here, we made use of the fast onset of inhibition by diazaborine to chase the maturation path in real-time from 27SA2 pre-rRNA containing pre-ribosomes localized in the nucleolus up to nearly mature 60S subunits shortly after their export into the cytoplasm. This allows for the first time to put protein assembly and disassembly reactions as well as pre-rRNA processing into a chronological context unraveling temporal and functional linkages during ribosome maturation. PMID:29294095

Ubiquitination dynamics in the early-branching eukaryote Giardia intestinalis

PubMed Central

Niño, Carlos A; Chaparro, Jenny; Soffientini, Paolo; Polo, Simona; Wasserman, Moises

2013-01-01

Ubiquitination is a highly dynamic and versatile posttranslational modification that regulates protein function, stability, and interactions. To investigate the roles of ubiquitination in a primitive eukaryotic lineage, we utilized the early-branching eukaryote Giardia intestinalis. Using a combination of biochemical, immunofluorescence-based, and proteomics approaches, we assessed the ubiquitination status during the process of differentiation in Giardia. We observed that different types of ubiquitin modifications present specific cellular and temporal distribution throughout the Giardia life cycle from trophozoites to cyst maturation. Ubiquitin signal was detected in the wall of mature cysts, and enzymes implicated in cyst wall biogenesis were identified as substrates for ubiquitination. Interestingly, inhibition of proteasome activity did not affect trophozoite replication and differentiation, while it caused a decrease in cyst viability, arguing for proteasome involvement in cyst wall maturation. Using a proteomics approach, we identified around 200 high-confidence ubiquitinated candidates that vary their ubiquitination status during differentiation. Our results indicate that ubiquitination is critical for several cellular processes in this primitive eukaryote. PMID:23613346

Individual condition and stream temperature influences early maturation of rainbow and steelhead trout, Oncorhynchus mykiss

Treesearch

John R. McMillan; Jason B. Dunham; Gordon H. Reeves; Justin S. Mills; Chris E. Jordan

2012-01-01

Alternative male phenotypes in salmonine fishes arise from individuals that mature as larger and older anadromous marine-migrants or as smaller and younger freshwater residents. To better understand the processes influencing the expression of these phenotypes we examined the influences of growth in length (fork length) and whole body lipid content in rainbow trout (...

Cytoskeleton-associated protein 5 and clathrin heavy chain binding regulates spindle assembly in mouse oocytes

PubMed Central

Wang, Dong-Hui; Han, Zhe; Kong, Xiang-Wei; Ma, Yu-Zhen; Yun, Zhi-Zhong; Liang, Cheng-Guang

2017-01-01

Mammalian oocyte meiotic maturation is the precondition of early embryo development. Lots of microtubules (MT)-associated proteins participate in oocyte maturation process. Cytoskeleton-associated protein 5 (CKAP5) is a member of the XMAP215 family that regulates microtubule dynamics during mitosis. However, its role in meiosis has not been fully studied. Here, we investigated the function of CKAP5 in mouse oocyte meiotic maturation and early embryo development. Western blot showed that CKAP5 expression increased from GVBD, maintaining at high level at metaphase, and decreased after late 1-cell stage. Confocal microscopy showed there is no specific accumulation of CKAP5 at interphase (GV, PN or 2-cell stage). However, once cells enter into meiotic or mitotic division, CKAP5 was localized at the whole spindle apparatus. Treatment of oocytes with the tubulin-disturbing reagents nocodazole (induces MTs depolymerization) or taxol (prevents MTs depolymerization) did not affect CKAP5 expression but led to a rearrangement of CKAP5. Further, knock-down of CKAP5 resulted in a failure of first polar body extrusion, serious defects in spindle assembly, and failure of chromosome alignment. Loss of CKAP5 also decreased early embryo development potential. Furthermore, co-immunoprecipitation showed that CKAP5 bound to clathrin heavy chain 1 (CLTC). Taken together, our results demonstrate that CKAP5 is important in oocyte maturation and early embryo development, and CKAP5 might work together with CLTC in mouse oocyte maturation. PMID:28177917

Effect of hybrid, maturity, and mechanical processing of corn silage on intake and digestibility by beef cattle.

PubMed

Andrae, J G; Hunt, C W; Pritchard, G T; Kennington, L R; Harrison, J H; Kezar, W; Mahanna, W

2001-09-01

A study involving a 2 x 2 x 2 factorial arrangement of treatments was conducted to evaluate effects of hybrid (Pioneer 3335 and 3489), maturity (half milkline and blacklayer), and mechanical processing (field chopper with and without on-board rollers engaged) on intake and digestibility of corn silage. Forty Angus steers (322 +/- 5.2 kg BW) were assigned to the eight silage treatments (five steers per treatment) and individually fed using electronic gates. Diets consisted of 60% corn silage and 40% chopped alfalfa hay (DM basis). Following a 5-d adaptation period, intake was measured for 7 d and subsequently fecal samples were collected for 5 d. Chromic oxide (5 g/d) was fed beginning 7 d before fecal sample collection and digestibility was determined by the ratio of Cr in the feed and feces. Steers were reallocated to treatments and these procedures were repeated, providing 10 observations per treatment. In addition, all silages were ruminally incubated in six mature cows for 0, 8, 16, 24, 48, and 96 h to determine extent and rate of DM, starch, NDF, and ADF disappearance. Processing increased DMI of hybrid 3489 but did not affect DMI of hybrid 3335 (hybrid x processing; P < 0.06). Total tract digestibility of DM, starch, NDF, and ADF decreased (P < 0.01) as plant maturity increased. Maturity tended to decrease starch digestibility more for hybrid 3489 than for hybrid 3335 (hybrid x maturity; P < 0.10). Processing increased (P < 0.01) starch digestibility but decreased (P < 0.01) NDF and ADF digestibility, resulting in no processing effect on DM digestibility. There was a numerical trend for processing to increase starch digestibility more for latethan for early-maturity corn silage (maturity x processing; P = 0.11). Processing increased in situ rates of DM and starch disappearance and maturity decreased in situ disappearance rates of starch and fiber. These data indicate that hybrid, maturity, and processing all affect corn silage digestibility. Mechanical processing of corn silage increased starch digestibility, which may have been associated with the observed decreased fiber digestibility.

The Role of Capsid Maturation on Adenovirus Priming for Sequential Uncoating*

PubMed Central

Pérez-Berná, Ana J.; Ortega-Esteban, Alvaro; Menéndez-Conejero, Rosa; Winkler, Dennis C.; Menéndez, Margarita; Steven, Alasdair C.; Flint, S. Jane; de Pablo, Pedro J.; San Martín, Carmen

2012-01-01

Adenovirus assembly concludes with proteolytic processing of several capsid and core proteins. Immature virions containing precursor proteins lack infectivity because they cannot properly uncoat, becoming trapped in early endosomes. Structural studies have shown that precursors increase the network of interactions maintaining virion integrity. Using different biophysical techniques to analyze capsid disruption in vitro, we show that immature virions are more stable than the mature ones under a variety of stress conditions and that maturation primes adenovirus for highly cooperative DNA release. Cryoelectron tomography reveals that under mildly acidic conditions mimicking the early endosome, mature virions release pentons and peripheral core contents. At higher stress levels, both mature and immature capsids crack open. The virus core is completely released from cracked capsids in mature virions, but it remains connected to shell fragments in the immature particle. The extra stability of immature adenovirus does not equate with greater rigidity, because in nanoindentation assays immature virions exhibit greater elasticity than the mature particles. Our results have implications for the role of proteolytic maturation in adenovirus assembly and uncoating. Precursor proteins favor assembly by establishing stable interactions with the appropriate curvature and preventing premature ejection of contents by tightly sealing the capsid vertices. Upon maturation, core organization is looser, particularly at the periphery, and interactions preserving capsid curvature are weakened. The capsid becomes brittle, and pentons are more easily released. Based on these results, we hypothesize that changes in core compaction during maturation may increase capsid internal pressure to trigger proper uncoating of adenovirus. PMID:22791715

Mothers' Knowledge of Early Adolescents' Activities following the Middle School Transition and Pubertal Maturation

ERIC Educational Resources Information Center

Laird, Robert D.; Marrero, Matthew D.

2011-01-01

This study tested a sequential mediation model to determine whether experiences, social cognitions, or parent-adolescent interactional processes account for lower levels of mothers' knowledge of adolescents' whereabouts and activities following early adolescents' transition into middle school (MS) and pubertal development. Cross-sectional data…

[The maturation steps of human immunodeficiency virus and the role of proteolysis].

PubMed

Bukrinskaia, A G; Grigor'ev, V B; Korablina, E V; Gur'ev, E L; Vorkunova, G K

2010-01-01

HIV-1 virions are as immature noninfectious particles lacking a central core. Shortly after budding, virions temporally mature and acquire cores and infectious activity. The cause of maturation remains poorly studied. We have revealed that the virions produced early after infection following 24-36 hours, never mature and remain noninfectious, and only virions produced 48-72 hours after infection mature. The mature virions contain 3 times more genomic viral RNA than "early" virus. The "early" virions contain the same proteolytically cleaved Gag proteins as mature virions in contrast to the accepted version. The virus protease inhibitor Indinavir sulfate (IS) fully blocks infectivity when added early after infection. The early proteolysis of Gag precursor in the infected cells and inclusion into the virions of cellularly cleaved matrix protein (cMA) are shown in the IS-treated cells. cMA is associated with genomic viral RNA.

Infant diet-related changes in syllable processing between 4 and 5 months: Implications for developing native language sensitivity

USDA-ARS?s Scientific Manuscript database

Since maturational processes triggering increased attunement to native language features in early infancy are sensitive to dietary factors, infant-diet related differences in brain processing of native-language speech stimuli might indicate variations in onset of this tuning process. We measured cor...

Self-Concept Development in Young Children

ERIC Educational Resources Information Center

Stenner, A. Jackson; Katzenmeyer, William G.

1976-01-01

Contrary to most theories, the child's concept of self crystalizes during the early school years, during which period a massive process of psychological and social maturation takes place. (Author/IRT)

Efficacy of Dendritic Cells Matured Early with OK-432 (Picibanil®), Prostaglandin E2, and Interferon-α as a Vaccine for a Hormone Refractory Prostate Cancer Cell Line

PubMed Central

Yoo, Changhee; Do, Hyun-Ah; Jeong, In Gab; Park, Hongzoo; Hwang, Jung-Jin; Hong, Jun Hyuk; Cho, Jin Seon; Choo, Myong-Soo; Ahn, Hanjong

2010-01-01

Dendritic cells (DCs) are potent antigen-presenting cells. OK432 (Picibanil®) was introduced as a potent stimulator of DC maturation in combination with prostaglandin-E2 and interferon-α. We compared the efficacy of a DC-prostate cancer vaccine using early-mature DCs stimulated with OK432, PGE2 and INF-α (OPA) with that of vaccines using other methods. On days 3 or 7 of DC culture, TNF-α (T), TNF-α and LPS (TL) or OPA were employed as maturation stimulators. DU145 cells subjected to heat stress were hybridized with mature DCs using polyethyleneglycol. T cells were sensitized by the hybrids, and their proliferative and cytokine secretion activities and cytotoxicity were measured. The yields of early-mature DCs were higher, compared to yields at the conventional maturation time (P<0.05). In the early maturation setting, the mean fusion ratios, calculated from the fraction of dual-positive cells, were 13.3%, 18.6%, and 39.9%, respectively (P=0.051) in the T only, TL, and OPA-treated groups. The function of cytotoxic T cells, which were sensitized with the hybrids containing DCs matured early with OPA, was superior to that using other methods. The antitumor effects of DC-DU145 hybrids generated with DCs subjected to early maturation with the OPA may be superior to that of the hybrids using conventional maturation methods. PMID:20808670

Efficacy of dendritic cells matured early with OK-432 (Picibanil), prostaglandin E2, and interferon-alpha as a vaccine for a hormone refractory prostate cancer cell line.

PubMed

Yoo, Changhee; Do, Hyun-Ah; Jeong, In Gab; Park, Hongzoo; Hwang, Jung-Jin; Hong, Jun Hyuk; Cho, Jin Seon; Choo, Myong-Soo; Ahn, Hanjong; Kim, Choung-Soo

2010-09-01

Dendritic cells (DCs) are potent antigen-presenting cells. OK432 (Picibanil) was introduced as a potent stimulator of DC maturation in combination with prostaglandin-E(2) and interferon-alpha. We compared the efficacy of a DC-prostate cancer vaccine using early-mature DCs stimulated with OK432, PGE2 and INF-alpha (OPA) with that of vaccines using other methods. On days 3 or 7 of DC culture, TNF-alpha (T), TNF-alpha and LPS (TL) or OPA were employed as maturation stimulators. DU145 cells subjected to heat stress were hybridized with mature DCs using polyethyleneglycol. T cells were sensitized by the hybrids, and their proliferative and cytokine secretion activities and cytotoxicity were measured. The yields of early-mature DCs were higher, compared to yields at the conventional maturation time (P<0.05). In the early maturation setting, the mean fusion ratios, calculated from the fraction of dual-positive cells, were 13.3%, 18.6%, and 39.9%, respectively (P=0.051) in the T only, TL, and OPA-treated groups. The function of cytotoxic T cells, which were sensitized with the hybrids containing DCs matured early with OPA, was superior to that using other methods. The antitumor effects of DC-DU145 hybrids generated with DCs subjected to early maturation with the OPA may be superior to that of the hybrids using conventional maturation methods.

Biosynthesis and intracellular movement of the melanosomal membrane glycoprotein gp75, the human b (brown) locus product

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vijayasaradhi, S.; Doskoch, P.M.; Houghton, A.N.

1991-10-01

A 75-kDa melanosomal glycoprotein (gp75) is the product of a gene that maps to the b (brown) locus, a genetic locus that determines coat color in the mouse. The b locus is conserved (88% identity) between mouse and human. The mouse monoclonal antibody TA99 was used to study the biosynthesis and processing of gp75. gp75 was synthesized as a 55-kDa polypeptide, glycosylated by addition and processing of five or more Asn-linked carbohydrate chains through the cis and trans Golgi, and transported to melanosomes as a mature 75-kDa form. Synthesis and processing of gp75 was rapid (T{sub 1/2} < 30 min),more » and early steps in processing were required for efficient export of gp75 was quite stable in the melanosome. Studies with inhibitors of steps in oligosaccharide processing showed that alternative forms of gp75 were generated during trimming reactions by mannosidase IA/IB and that further maturation resulted in the two mature forms of gp75. The authors purpose that the kinetics of biosynthesis and processing reflect events in the biogenesis and maturation of melanosomes.« less

Neural Indices of Semantic Processing in Early Childhood Distinguish Eventual Stuttering Persistence and Recovery

ERIC Educational Resources Information Center

Kreidler, Kathryn; Wray, Amanda Hampton; Usler, Evan; Weber, Christine

2017-01-01

Purpose: Maturation of neural processes for language may lag in some children who stutter (CWS), and event-related potentials (ERPs) distinguish CWS who have recovered from those who have persisted. The current study explores whether ERPs indexing semantic processing may distinguish children who will eventually persist in stuttering…

Maturity status influences the relative age effect in national top level youth alpine ski racing and soccer

PubMed Central

Müller, Lisa; Gonaus, Christoph; Perner, Christoph; Müller, Erich; Raschner, Christian

2017-01-01

Since the relative age effect (RAE) characterizes a problem in all age categories of alpine ski racing and soccer and the fact that, yet, to date the underlying factors have not been well investigated, the aim of the present study was to assess the influence of the biological maturity status on the RAE among youth alpine ski racers (YSR) and soccer players (SP). In total, 183 male and female YSR selected for national final races and 423 male SP selected for Elite Youth Development Centres were investigated. Additionally, a comparison group of 413 non-athletes was evaluated. The birth months were split into four relative age quarters. The biological maturity status was assessed by the age at peak height velocity (APHV) method; according to the M±SD of the comparison group, the athletes were divided into normal, early and late maturing. Chi2-tests indicated a significant RAE among YSR (χ2(3,N = 183) = 18.0; p<0.001; ω = 0.31) and SP (χ2(3,N = 423) = 33.1; p<0.001; ω = 0.28). In total, only a small number of late maturing athletes were present (0.5–2.3%). Among relatively younger athletes, high percentages of early maturing athletes were found (43.1–43.3%). The findings indicate that relatively younger and less mature athletes are marginalized or totally excluded in alpine ski racing and soccer. Thus, selection criteria in both sports are effectively based on early biological development and relatively older age, both of which should be considered in future in the talent selection process. In this context, the easy feasible method of assessing the APHV can be used. PMID:28759890

Individual condition and stream temperature influence early maturation of rainbow and steelhead trout, ncorhynchus mykiss

USGS Publications Warehouse

McMillan, John R.; Dunham, Jason B.; Reeves, Gordon H.; Mills, Justin S.; Jordan, Chris E.

2012-01-01

Alternative male phenotypes in salmonine fishes arise from individuals that mature as larger and older anadromous marine-migrants or as smaller and younger freshwater residents. To better understand the processes influencing the expression of these phenotypes we examined the influences of growth in length (fork length) and whole body lipid content in rainbow trout (Oncorhynchus mykiss). Fish were sampled from the John Day River basin in northeast Oregon where both anadromous ("steelhead") and freshwater resident rainbow trout coexist. Larger males with higher lipid levels had a greater probability of maturing as a resident at age-1+. Among males, 38% were maturing overall, and the odds ratios of the logistic model indicated that the probability of a male maturing early as a resident at age-1+ increased 49% (95% confidence interval (CI) = 23-81%) for every 5 mm increase in length and 33% (95% CI = 10-61%) for every 0.5% increase in whole body lipid content. There was an inverse association between individual condition and water temperature as growth was greater in warmer streams while whole body lipid content was higher in cooler streams. Our results support predictions from life history theory and further suggest that relationships between individual condition, maturation, and environmental variables (e.g., water temperature) are shaped by complex developmental and evolutionary influences.

Continuous Change in Membrane and Membrane-Skeleton Organization During Development From Proerythroblast to Senescent Red Blood Cell

PubMed Central

Minetti, Giampaolo; Achilli, Cesare; Perotti, Cesare; Ciana, Annarita

2018-01-01

Within the context of erythropoiesis and the possibility of producing artificial red blood cells (RBCs) in vitro, a most critical step is the final differentiation of enucleated erythroblasts, or reticulocytes, to a fully mature biconcave discocyte, the RBC. Reviewed here is the current knowledge about this fundamental maturational process. By combining literature data with our own experimental evidence we propose that the early phase in the maturation of reticulocytes to RBCs is driven by a membrane raft-based mechanism for the sorting of disposable membrane proteins, mostly the no longer needed transferrin receptor (TfR), to the multivesicular endosome (MVE) as cargo of intraluminal vesicles that are subsequently exocytosed as exosomes, consistently with the seminal and original observation of Johnstone and collaborators of more than 30 years ago (Pan BT, Johnstone RM. Cell. 1983;33:967-978). According to a strikingly selective sorting process, the TfR becomes cargo destined to exocytosis while other molecules, including the most abundant RBC transmembrane protein, band 3, are completely retained in the cell membrane. It is also proposed that while this process could be operating in the early maturational steps in the bone marrow, additional mechanism(s) must be at play for the final removal of the excess reticulocyte membrane that is observed to occur in the circulation. This processing will most likely require the intervention of the spleen, whose function is also necessary for the continuous remodeling of the RBC membrane all along this cell's circulatory life. PMID:29632498

Resting heart rate in infants and toddlers: variations associated with early infant diet and the omega 3 fatty acid DHA

USDA-ARS?s Scientific Manuscript database

Although early postnatal nutrition can have long-term effects on developmental processes, the influence of infant diet on the maturation of cardiac development has not been documented. To study this relationship we recorded resting heart-rate (HR) in awake, healthy infants and toddlers exclusively b...

Commonly used disinfectants fail to eradicate Salmonella enterica biofilms from food contact surface materials.

PubMed

Corcoran, M; Morris, D; De Lappe, N; O'Connor, J; Lalor, P; Dockery, P; Cormican, M

2014-02-01

Salmonellosis is the second most common cause of food-borne illness worldwide. Contamination of surfaces in food processing environments may result in biofilm formation with a risk of food contamination. Effective decontamination of biofilm-contaminated surfaces is challenging. Using the CDC biofilm reactor, the activities of sodium hypochlorite, sodium hydroxide, and benzalkonium chloride were examined against an early (48-h) and relatively mature (168-h) Salmonella biofilm. All 3 agents result in reduction in viable counts of Salmonella; however, only sodium hydroxide resulted in eradication of the early biofilm. None of the agents achieved eradication of mature biofilm, even at the 90-min contact time. Studies of activity of chemical disinfection against biofilm should include assessment of activity against mature biofilm. The difficulty of eradication of established Salmonella biofilm serves to emphasize the priority of preventing access of Salmonella to postcook areas of food production facilities.

The influence of pubertal timing and stressful life events on depression and delinquency among Chinese adolescents.

PubMed

Chen, Jie; Yu, Jing; Wu, Yun; Zhang, Jianxin

2015-06-01

This study aimed to investigate the influences of pubertal timing and stressful life events on Chinese adolescents' depression and delinquency. Sex differences in these influences were also examined. A large sample with 4,228 participants aged 12-15 years (53% girls) was recruited in Beijing, China. Participants' pubertal development, stressful life events, depressive symptoms, and delinquency were measured using self-reported questionnaires. Both early maturing girls and boys displayed more delinquency than their same-sex on-time and late maturing peers. Early maturing girls displayed more depressive symptoms than on-time and late maturing girls, but boys in the three maturation groups showed similar levels of depressive symptoms. The interactive effects between early pubertal timing and stressful life events were significant in predicting depression and delinquency, particularly for girls. Early pubertal maturation is an important risk factor for Chinese adolescents' depression and delinquency. Stressful life events intensified the detrimental effects of early pubertal maturation on adolescents' depression and delinquency, particularly for girls. © 2015 The Institute of Psychology, Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Early Adversity, Elevated Stress Physiology, Accelerated Sexual Maturation, and Poor Health in Females

ERIC Educational Resources Information Center

Belsky, Jay; Ruttle, Paula L.; Boyce, W. Thomas; Armstrong, Jeffrey M.; Essex, Marilyn J.

2015-01-01

Evolutionary-minded developmentalists studying predictive-adaptive-response processes linking childhood adversity with accelerated female reproductive development and health scientists investigating the developmental origins of health and disease (DOoHaD) may be tapping the same process, whereby longer-term health costs are traded off for…

Physical Activity-Related Injury Profile in Children and Adolescents According to Their Age, Maturation, and Level of Sports Participation.

PubMed

Costa E Silva, Lara; Fragoso, Maria Isabel; Teles, Júlia

Physical activity (PA) is beneficial, enhancing healthy development. However, one-third of school-age children practicing sports regularly suffer from an injury. These injuries are associated with sex, chronological age, and PA level. To identify the importance of age, PA level, and maturity as predictors of injury in Portuguese youth. Descriptive epidemiological study. Level 3. Information about injury and PA level was assessed via 2 questionnaires (LESADO RAPIL II) from 647 subjects aged 10 to 17 years. Maturity offset according to Mirwald (time before or after peak height velocity) and Tanner-Whitehouse III bone age estimates were used to evaluate maturation. Binary logistic regression and gamma regression were used to determine significant predictors of injury and injury rate. Injury occurrence was higher for both sexes in recreational, school, and federated athletes (athletes engaged in sports that are regulated by their respective federations, with formal competition). These injuries also increased with age in boys and in the higher maturity offset group in girls. Injury rate was higher for both sexes in the no sports participation group. Early-maturing girls, with higher bone age and lower maturity offset, showed higher injury rate. Injuries in Portuguese youth were related to PA level, age, and biological maturation. Recreational, school, and federated athletes had more injury ocurrences while subjects with no sports participation had higher injury risk. Older subjects had more injuries. Early-maturing girls that had just passed peak height velocity may be particularly vulnerable to risk of sports injury because of the growing process. Increased knowledge about injury with specific PA exposure data is important to an overall risk management strategy. This study has deepened the association between injury and biological maturation variables.

Translational control by cytoplasmic polyadenylation during Xenopus oocyte maturation: characterization of cis and trans elements and regulation by cyclin/MPF.

PubMed

McGrew, L L; Richter, J D

1990-11-01

The expression of certain maternal mRNAs during oocyte maturation is regulated by cytoplasmic polyadenylation. To understand this process, we have focused on a maternal mRNA from Xenopus termed G10. This mRNA is stored in the cytoplasm of stage 6 oocytes until maturation when the process of poly(A) elongation stimulates its translation. Deletion analysis of the 3' untranslated region of G10 RNA has revealed that two sequence elements, UUUUUUAU and AAUAAA were both necessary and sufficient for polyadenylation and polysomal recruitment. In this communication, we have defined the U-rich region that is optimal for polyadenylation as UUUUUUAUAAAG, henceforth referred to as the cytoplasmic polyadenylation element (CPE). We have also identified unique sequence requirements in the 3' terminus of the RNA that can modulate polyadenylation even in the presence of wild-type cis elements. A time course of cytoplasmic polyadenylation in vivo shows that it is an early event of maturation and that it requires protein synthesis within the first 15 min of exposure to progesterone. MPF and cyclin can both induce polyadenylation but, at least with respect to MPF, cannot obviate the requirement for protein synthesis. To identify factors that may be responsible for maturation-specific polyadenylation, we employed extracts from oocytes and unfertilized eggs, the latter of which correctly polyadenylates exogenously added RNA. UV crosslinking demonstrated that an 82 kd protein binds to the U-rich CPE in egg, but not oocyte, extracts. The data suggest that progesterone, either in addition to or through MPF/cyclin, induces the synthesis of a factor during very early maturation that stimulates polyadenylation.(ABSTRACT TRUNCATED AT 250 WORDS)

The ESCRT regulator Did2 maintains the balance between long-distance endosomal transport and endocytic trafficking

PubMed Central

Haag, Carl

2017-01-01

In highly polarised cells, like fungal hyphae, early endosomes function in both endocytosis as well as long-distance transport of various cargo including mRNA and protein complexes. However, knowledge on the crosstalk between these seemingly different trafficking processes is scarce. Here, we demonstrate that the ESCRT regulator Did2 coordinates endosomal transport in fungal hyphae of Ustilago maydis. Loss of Did2 results in defective vacuolar targeting, less processive long-distance transport and abnormal shuttling of early endosomes. Importantly, the late endosomal protein Rab7 and vacuolar protease Prc1 exhibit increased shuttling on these aberrant endosomes suggesting defects in endosomal maturation and identity. Consistently, molecular motors fail to attach efficiently explaining the disturbed processive movement. Furthermore, the endosomal mRNP linker protein Upa1 is hardly present on endosomes resulting in defects in long-distance mRNA transport. In conclusion, the ESCRT regulator Did2 coordinates precise maturation of endosomes and thus provides the correct membrane identity for efficient endosomal long-distance transport. PMID:28422978

It's about Timing and Change: Pubertal Transition Effects on Symptoms of Major Depression among African American Youths.

ERIC Educational Resources Information Center

Ge, Xiaojia; Kim, Irene J.; Brody, Gene H.; Conger, Rand D.; Simons, Ronald L.; Gibbons, Frederick X.; Cutrona, Carolyn E.

2003-01-01

Examined effects of early physical maturation and accelerated pubertal changes on symptoms of major depression among 639 African American adolescents. Found that for girls, early maturation was consistently associated with elevated levels of depressive symptoms. For boys, early maturers showed elevated depression only at age 11, with symptoms…

Early infant diet and the omega 3 fatty acid DHA: effects on resting cardiovascular activity and behavioral development during the first half-year of life

USDA-ARS?s Scientific Manuscript database

The course of postnatal maturation of cardiac control has implications for cognitive development, but the influence of early nutrition on underlying processes is still being defined. This investigation evaluated the effects of different diets on interactions among these variables during the first ha...

Early life stress accelerates behavioral and neural maturation of the hippocampus in male mice.

PubMed

Bath, K; Manzano-Nieves, G; Goodwill, H

2016-06-01

Early life stress (ELS) increases the risk for later cognitive and emotional dysfunction. ELS is known to truncate neural development through effects on suppressing cell birth, increasing cell death, and altering neuronal morphology, effects that have been associated with behavioral profiles indicative of precocious maturation. However, how earlier silencing of growth drives accelerated behavioral maturation has remained puzzling. Here, we test the novel hypothesis that, ELS drives a switch from growth to maturation to accelerate neural and behavioral development. To test this, we used a mouse model of ELS, fragmented maternal care, and a cross-sectional dense sampling approach focusing on hippocampus and measured effects of ELS on the ontogeny of behavioral development and biomarkers of neural maturation. Consistent with previous work, ELS was associated with an earlier developmental decline in expression of markers of cell proliferation (Ki-67) and differentiation (doublecortin). However, ELS also led to a precocious arrival of Parvalbumin-positive cells, led to an earlier switch in NMDA receptor subunit expression (marker of synaptic maturity), and was associated with an earlier rise in myelin basic protein expression (key component of the myelin sheath). In addition, in a contextual fear-conditioning task, ELS accelerated the timed developmental suppression of contextual fear. Together, these data provide support for the hypothesis that ELS serves to switch neurodevelopment from processes of growth to maturation and promotes accelerated development of some forms of emotional learning. Copyright © 2016 Elsevier Inc. All rights reserved.

Quantitative Evaluation of Collagen Crosslinks and Corresponding Tensile Mechanical Properties in Mouse Cervical Tissue during Normal Pregnancy

PubMed Central

Yoshida, Kyoko; Jiang, Hongfeng; Kim, MiJung; Vink, Joy; Cremers, Serge; Paik, David; Wapner, Ronald; Mahendroo, Mala; Myers, Kristin

2014-01-01

The changes in the mechanical integrity of the cervix during pregnancy have implications for a successful delivery. Cervical collagens are known to remodel extensively in mice with progressing gestation leading to a soft cervix at term. During this process, mature crosslinked collagens are hypothesized to be replaced with immature less crosslinked collagens to facilitate cervical softening and ripening. To determine the mechanical role of collagen crosslinks during normal mouse cervical remodeling, tensile load-to-break tests were conducted for the following time points: nonpregnant (NP), gestation day (d) 6, 12, 15, 18 and 24 hr postpartum (PP) of the 19-day gestation period. Immature crosslinks (HLNL and DHLNL) and mature crosslinks (DPD and PYD) were measured using ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). There were no significant changes in the total immature crosslink density (HLNL+DHLNL mol per collagen mol) throughout normal mouse gestation (range: 0.31–0.49). Total mature crosslink density (PYD+DPD mol per collagen mol) decreased significantly in early softening from d6 to d15 (d6: 0.17, d12: 0.097, d15: 0.026) and did not decrease with further gestation. The maturity ratio (total mature to total immature crosslinks) significantly decreased in early softening from d6 to d15 (d6: 0.2, d15: 0.074). All of the measured crosslinks correlated significantly with a measure of tissue stiffness and strength, with the exception of the immature crosslink HLNL. This data provides quantitative evidence to support the hypothesis that as mature crosslinked collagens decline, they are replaced by immature collagens to facilitate increased tissue compliance in the early softening period from d6 to d15. PMID:25397407

Maturational and Non-Maturational Factors in Heritage Language Acquisition

ERIC Educational Resources Information Center

Moon, Ji Hye

2012-01-01

This dissertation aims to understand the maturational and non-maturational aspects of early bilingualism and language attrition in heritage speakers who have acquired their L1 incompletely in childhood. The study highlights the influential role of age and input dynamics in early L1 development, where the timing of reduction in L1 input and the…

The expression of human natural killer cell receptors in early life.

PubMed

Sundström, Y; Nilsson, C; Lilja, G; Kärre, K; Troye-Blomberg, M; Berg, L

2007-01-01

Natural killer (NK) cells play an important role in tumour immunosurveillance and the early defence against viral infections. Recognition of altered cells (i.e. infected- or tumour-cells) is achieved through a multiple receptor recognition strategy which gives the NK cells inhibitory or activating signals depending on the ligands present on the target cell. NK cells originate from the bone marrow where they develop and proliferate. However, further maturation processes and homeostasis of NK cells in peripheral blood are not well understood. To determine the proportions of cells and the expression of NK cell receptors, mononuclear cells from children at three time points during early childhood were compared, i.e. cord blood (CB), 2 and 5 years of age. The proportion of NK cells was high in CB, but the interferon-gamma (IFN-gamma) production low compared to later in life. In contrast, the proportion of T cells was low in CB. This may indicate a deviation of the regulatory function of NK cells in CB compared to later in life, implying an importance of innate immunity in early life before the adaptive immune system matures. Additionally, we found that the proportion of LIR-1(+) NK cells increased with increasing age while CD94(+)NKG2C(-) (NKG2A(+)) NK cells and the level of expression of NKG2D, NKp30 and NKp46 decreased with age. These age related changes in NK cell populations defined by the expression of activating and inhibitory receptors may be the result of pathogen exposure and/or a continuation of the maturation process that begins in the bone marrow.

Early Pubertal Maturation and Internalizing Problems in Adolescence: Sex Differences in the Role of Cortisol Reactivity to Interpersonal Stress

ERIC Educational Resources Information Center

Natsuaki, Misaki N.; Klimes-Dougan, Bonnie; Ge, Xiaojia; Shirtcliff, Elizabeth A.; Hastings, Paul D.; Zahn-Waxler, Carolyn

2009-01-01

An accumulating body of literature has shown a link between early pubertal maturation and internalizing problems, particularly among girls. Our knowledge is, however, limited with regard to what accounts for this association. Based on a hypothesis that early maturing girls have heightened stress sensitivity that increases the risk of internalizing…

Age-Related Differences In White Matter Tract Microstructure Are Associated With Cognitive Performance From Childhood to Adulthood

PubMed Central

Peters, Bart D.; Ikuta, Toshikazu; DeRosse, Pamela; John, Majnu; Burdick, Katherine E.; Gruner, Patricia; Prendergast, Daniel M.; Szeszko, Philip R.; Malhotra, Anil K.

2013-01-01

Background Age-related differences in white matter (WM) tract microstructure have been well-established across the lifespan. In the present cross-sectional study we examined whether these differences are associated with neurocognitive performance from childhood to late adulthood. Methods Diffusion tensor imaging was performed in 296 healthy subjects aged 8–68 years (mean=29.6, SD=14.6). The corpus callosum, two projection tracts, and five association tracts were traced using probabilistic tractography. A neurocognitive test battery was used to assess speed of processing, attention, spatial working memory, verbal functioning, visual learning and executive functioning. Linear mediation models were used to examine whether differences in WM tract fractional anisotropy (FA) were associated with neurocognitive performance, independent of the effect of age. Results From childhood to early adulthood, higher FA of the cingulum bundle and inferior fronto-occipital fasciculus (IFOF) was associated with higher executive functioning and global cognitive functioning, respectively, independent of the effect of age. When adjusting for speed of processing, FA of the IFOF was no longer associated with performance in the other cognitive domains with the exception of visual learning. From early adulthood to late adulthood, WM tract FA was not associated with cognitive performance independent of the age effect. Conclusions The cingulum bundle may play a critical role in protracted maturation of executive functioning. The IFOF may play a key role in maturation of visual learning, and may act as a central ‘hub’ in global cognitive maturation by subserving maturation of processing speed. PMID:23830668

The maturation of cortical sleep rhythms and networks over early development.

PubMed

Chu, C J; Leahy, J; Pathmanathan, J; Kramer, M A; Cash, S S

2014-07-01

Although neuronal activity drives all aspects of cortical development, how human brain rhythms spontaneously mature remains an active area of research. We sought to systematically evaluate the emergence of human brain rhythms and functional cortical networks over early development. We examined cortical rhythms and coupling patterns from birth through adolescence in a large cohort of healthy children (n=384) using scalp electroencephalogram (EEG) in the sleep state. We found that the emergence of brain rhythms follows a stereotyped sequence over early development. In general, higher frequencies increase in prominence with striking regional specificity throughout development. The coordination of these rhythmic activities across brain regions follows a general pattern of maturation in which broadly distributed networks of low-frequency oscillations increase in density while networks of high frequency oscillations become sparser and more highly clustered. Our results indicate that a predictable program directs the development of key rhythmic components and physiological brain networks over early development. This work expands our knowledge of normal cortical development. The stereotyped neurophysiological processes observed at the level of rhythms and networks may provide a scaffolding to support critical periods of cognitive growth. Furthermore, these conserved patterns could provide a sensitive biomarker for cortical health across development. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

The maturation of cortical sleep rhythms and networks over early development

PubMed Central

Chu, CJ; Leahy, J; Pathmanathan, J; Kramer, MA; Cash, SS

2014-01-01

Objective Although neuronal activity drives all aspects of cortical development, how human brain rhythms spontaneously mature remains an active area of research. We sought to systematically evaluate the emergence of human brain rhythms and functional cortical networks over early development. Methods We examined cortical rhythms and coupling patterns from birth through adolescence in a large cohort of healthy children (n=384) using scalp electroencephalogram (EEG) in the sleep state. Results We found that the emergence of brain rhythms follows a stereotyped sequence over early development. In general, higher frequencies increase in prominence with striking regional specificity throughout development. The coordination of these rhythmic activities across brain regions follows a general pattern of maturation in which broadly distributed networks of low-frequency oscillations increase in density while networks of high frequency oscillations become sparser and more highly clustered. Conclusion Our results indicate that a predictable program directs the development of key rhythmic components and physiological brain networks over early development. Significance This work expands our knowledge of normal cortical development. The stereotyped neurophysiological processes observed at the level of rhythms and networks may provide a scaffolding to support critical periods of cognitive growth. Furthermore, these conserved patterns could provide a sensitive biomarker for cortical health across development. PMID:24418219

Retroviral proteases and their roles in virion maturation.

PubMed

Konvalinka, Jan; Kräusslich, Hans-Georg; Müller, Barbara

2015-05-01

Proteolytic processing of viral polyproteins is essential for retrovirus infectivity. Retroviral proteases (PR) become activated during or after assembly of the immature, non-infectious virion. They cleave viral polyproteins at specific sites, inducing major structural rearrangements termed maturation. Maturation converts retroviral enzymes into their functional form, transforms the immature shell into a metastable state primed for early replication events, and enhances viral entry competence. Not only cleavage at all PR recognition sites, but also an ordered sequence of cleavages is crucial. Proteolysis is tightly regulated, but the triggering mechanisms and kinetics and pathway of morphological transitions remain enigmatic. Here, we outline PR structures and substrate specificities focusing on HIV PR as a therapeutic target. We discuss design and clinical success of HIV PR inhibitors, as well as resistance development towards these drugs. Finally, we summarize data elucidating the role of proteolysis in maturation and highlight unsolved questions regarding retroviral maturation. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of Microbiota in Infants and its Role in Maturation of Gut Mucosa and Immune System.

PubMed

Ximenez, Cecilia; Torres, Javier

2017-11-01

Dysbiosis of the gut microbiota has been associated with increasing numbers of diseases, including obesity, diabetes, inflammatory bowel disease, asthma, allergy, cancer and even neurologic or behavioral disorders. The other side of the coin is that a healthy microbiota leads to a healthy human development, to a mature and well trained immune system and to an efficient metabolic machinery. What we have learned in adults is in the end the result of a good start, a programmed, healthy development of the microbiota that must occur in the early years of life, probably even starting during the fetal stage. This review aims to present and discuss reports that helps us understand what we have learned of the development of microbiota during the early times of life, from pregnancy to delivery to the early years after birth. The impact of the establishment of "healthy" bacterial communities on human surfaces in the maturation of epithelia, immune system and metabolism will also be discussed. The right process of maturation of the bacterial communities that establish a symbiosis with human surfaces depends on a number of environmental, genetic and temporal factors that need to be understand in order to have tools to monitor a healthy development and eventually intervene to correct undesired courses. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

Acoustic and Petrophysical Evolution of Organic-Rich Chalk Following Maturation Induced by Unconfined Pyrolysis

NASA Astrophysics Data System (ADS)

Shitrit, Omri; Hatzor, Yossef H.; Feinstein, Shimon; Vinegar, Harold J.

2017-12-01

Thermal maturation is known to influence the rock physics of organic-rich rocks. While most studies were performed on low-porosity organic-rich shales, here we examine the effect of thermal maturation on a high-porosity organic-rich chalk. We compare the physical properties of native state immature rock with the properties at two pyrolysis-simulated maturity levels: early-mature and over-mature. We further evaluate the applicability of results from unconfined pyrolysis experiments to naturally matured rock properties. Special attention is dedicated to the elastic properties of the organic phase and the influence of bitumen and kerogen contents. Rock physics is studied based on confined petrophysical measurements of porosity, density and permeability, and measurements of bedding-normal acoustic velocities at estimated field stresses. Geochemical parameters like total organic carbon (TOC), bitumen content and thermal maturation indicators are used to monitor variations in density and volume fraction of each phase. We find that porosity increases significantly upon pyrolysis and that P wave velocity decreases in accordance. Solids density versus TOC relationships indicate that the kerogen increases its density from 1.43 to 1.49 g/cc at the immature and early-mature stages to 2.98 g/cc at the over-mature stage. This density value is unusually high, although increase in S wave velocity and backscatter SEM images of the over-mature samples verify that the over-mature kerogen is significantly denser and stiffer. Using the petrophysical and acoustic properties, the elastic moduli of the rock are estimated by two Hashin-Shtrikman (HS)-based models: "HS + BAM" and "HS kerogen." The "HS + BAM" model is calibrated to the post-pyrolysis measurements to describe the mechanical effect of the unconfined pyrolysis on the rock. The absence of compaction in the pyrolysis process causes the post-pyrolysis samples to be extremely porous. The "HS kerogen" model, which simulates a kerogen-supported matrix, depicts a compacted version of the matrix and is believed to be more representative of a naturally matured rock. Rock physics analysis using the "HS kerogen" model indicates strong mechanical dominance of porosity and organic content, and only small maturity-associated effects.

[Myonuclear domain and microtubule proteome during skeletal muscle maturation].

PubMed

Couturier, Nathalie; Gache, Vincent

2017-11-01

In the normal course of muscle fiber development, myonuclei actively position and adapt a precise localization in mature fibers, shaping MyoNuclear Domains (MNDs). Myonuclei positioning in fibers appears to be essential for muscle function as defects in MNDs settings are always associated with dysfunction (i.e., centronuclear myopathy, sarcopenia). Previous studies have shown that myonuclei positioning in fibers is reversible, suggesting that in pathologies presenting MNDs impairment, myonuclei could be re-addressed to the "correct" position in fibers and this could benefit to muscle function. Cytoskeleton networks, and particularly microtubules, have been implicated in early nuclei localization in myotubes. As the microtubule network is completely redesigned during muscle maturation, we hypothesized that "microtubules associated proteomes" would change between immature and mature fibers and contribute to a microtubule-dependent process resulting in MNDs setting and maintenance in mature fibers. We performed an in vitro biochemical approach to isolate microtubules partners in immature (myotubes) and mature myofibers. Using mass-spectrometry identification, we selected 244 candidates, differentially associated/expressed with microtubules during myofiber maturation and potentially controlling MNDs settings. We are currently conducting a siRNA screen approach on these candidates to decipher their respective implication in early and late phases of MNDs establishment, using an unbiased assay developed by our team allowing statistical analysis of MNDs regarding myonuclei content. This approach will lead to the identification of new pathways related to nuclear positioning and MNDs setting in normal condition and in myopathies associated to MNDs impairment such as CNMs. © 2017 médecine/sciences – Inserm.

Neural activity during natural viewing of Sesame Street statistically predicts test scores in early childhood.

PubMed

Cantlon, Jessica F; Li, Rosa

2013-01-01

It is not currently possible to measure the real-world thought process that a child has while observing an actual school lesson. However, if it could be done, children's neural processes would presumably be predictive of what they know. Such neural measures would shed new light on children's real-world thought. Toward that goal, this study examines neural processes that are evoked naturalistically, during educational television viewing. Children and adults all watched the same Sesame Street video during functional magnetic resonance imaging (fMRI). Whole-brain intersubject correlations between the neural timeseries from each child and a group of adults were used to derive maps of "neural maturity" for children. Neural maturity in the intraparietal sulcus (IPS), a region with a known role in basic numerical cognition, predicted children's formal mathematics abilities. In contrast, neural maturity in Broca's area correlated with children's verbal abilities, consistent with prior language research. Our data show that children's neural responses while watching complex real-world stimuli predict their cognitive abilities in a content-specific manner. This more ecologically natural paradigm, combined with the novel measure of "neural maturity," provides a new method for studying real-world mathematics development in the brain.

Depressive Symptomatology among Very Early Maturing Girls.

ERIC Educational Resources Information Center

Rierdan, Jill; Koff, Elissa

1991-01-01

The relationship between very early menarche and depression was studied in a sample of 488 girls (336 sixth graders and 152 seventh graders), less than 10 percent of whom were very early maturers. Very early menarche was associated with higher levels of depression than was more normative development. (SLD)

Quantification of diffusion tensor imaging in normal white matter maturation of early childhood using an automated processing pipeline.

PubMed

Loh, K B; Ramli, N; Tan, L K; Roziah, M; Rahmat, K; Ariffin, H

2012-07-01

The degree and status of white matter myelination can be sensitively monitored using diffusion tensor imaging (DTI). This study looks at the measurement of fractional anistropy (FA) and mean diffusivity (MD) using an automated ROI with an existing DTI atlas. Anatomical MRI and structural DTI were performed cross-sectionally on 26 normal children (newborn to 48 months old), using 1.5-T MRI. The automated processing pipeline was implemented to convert diffusion-weighted images into the NIfTI format. DTI-TK software was used to register the processed images to the ICBM DTI-81 atlas, while AFNI software was used for automated atlas-based volumes of interest (VOIs) and statistical value extraction. DTI exhibited consistent grey-white matter contrast. Triphasic temporal variation of the FA and MD values was noted, with FA increasing and MD decreasing rapidly early in the first 12 months. The second phase lasted 12-24 months during which the rate of FA and MD changes was reduced. After 24 months, the FA and MD values plateaued. DTI is a superior technique to conventional MR imaging in depicting WM maturation. The use of the automated processing pipeline provides a reliable environment for quantitative analysis of high-throughput DTI data. Diffusion tensor imaging outperforms conventional MRI in depicting white matter maturation. • DTI will become an important clinical tool for diagnosing paediatric neurological diseases. • DTI appears especially helpful for developmental abnormalities, tumours and white matter disease. • An automated processing pipeline assists quantitative analysis of high throughput DTI data.

Maturity group classification and maturity locus genotyping of early-maturing soybean varieties from high-latitude cold regions.

PubMed

Jia, Hongchang; Jiang, Bingjun; Wu, Cunxiang; Lu, Wencheng; Hou, Wensheng; Sun, Shi; Yan, Hongrui; Han, Tianfu

2014-01-01

With the migration of human beings, advances of agricultural sciences, evolution of planting patterns and global warming, soybeans have expanded to both tropical and high-latitude cold regions (HCRs). Unlike other regions, HCRs have much more significant and diverse photoperiods and temperature conditions over seasons or across latitudes, and HCR soybeans released there show rich diversity in maturity traits. However, HCR soybeans have not been as well classified into maturity groups (MGs) as other places. Therefore, it is necessary to identify MGs in HCRs and to genotype the maturity loci. Local varieties were collected from the northern part of Northeast China and the far-eastern region of Russia. Maturity group reference (MGR) soybeans of MGs MG000, MG00, and MG0 were used as references during field experiments. Both local varieties and MGR soybeans were planted for two years (2010-2011) in Heihe (N 50°15', E 127°27', H 168.5 m), China. The days to VE (emergence), R1 (beginning bloom) and R7 (beginning maturity) were recorded and statistically analyzed. Furthermore, some varieties were further genotyped at four molecularly-identified maturity loci E1, E2, E3 and E4. The HCR varieties were classified into MG0 or even more early-maturing. In Heihe, some varieties matured much earlier than MG000, which is the most early-maturing known MG, and clustered into a separate group. We designated the group as MG0000, following the convention of MGs. HCR soybeans had relatively stable days to beginning bloom from emergence. The HCR varieties diversified into genotypes of E1, E2, E3 and E4. These loci had different effects on maturity. HCRs diversify early-maturing MGs of soybean. MG0000, a new MG that matures much earlier than known MGs, was developed. HCR soybean breeding should focus more on shortening post-flowering reproductive growth. E1, E2, E3, and E4 function differentially.

Capability maturity models for offshore organisational management.

PubMed

Strutt, J E; Sharp, J V; Terry, E; Miles, R

2006-12-01

The goal setting regime imposed by the UK safety regulator has important implications for an organisation's ability to manage health and safety related risks. Existing approaches to safety assurance based on risk analysis and formal safety assessments are increasingly considered unlikely to create the step change improvement in safety to which the offshore industry aspires and alternative approaches are being considered. One approach, which addresses the important issue of organisational behaviour and which can be applied at a very early stage of design, is the capability maturity model (CMM). The paper describes the development of a design safety capability maturity model, outlining the key processes considered necessary to safety achievement, definition of maturity levels and scoring methods. The paper discusses how CMM is related to regulatory mechanisms and risk based decision making together with the potential of CMM to environmental risk management.

Characterization of Dedifferentiating Human Mature Adipocytes from the Visceral and Subcutaneous Fat Compartments: Fibroblast-Activation Protein Alpha and Dipeptidyl Peptidase 4 as Major Components of Matrix Remodeling

PubMed Central

Lessard, Julie; Pelletier, Mélissa; Biertho, Laurent; Biron, Simon; Marceau, Simon; Hould, Frédéric-Simon; Lebel, Stéfane; Moustarah, Fady; Lescelleur, Odette; Marceau, Picard; Tchernof, André

2015-01-01

Mature adipocytes can reverse their phenotype to become fibroblast-like cells. This is achieved by ceiling culture and the resulting cells, called dedifferentiated fat (DFAT) cells, are multipotent. Beyond the potential value of these cells for regenerative medicine, the dedifferentiation process itself raises many questions about cellular plasticity and the pathways implicated in cell behavior. This work has been performed with the objective of obtaining new information on adipocyte dedifferentiation, especially pertaining to new targets that may be involved in cellular fate changes. To do so, omental and subcutaneous mature adipocytes sampled from severely obese subjects have been dedifferentiated by ceiling culture. An experimental design with various time points along the dedifferentiation process has been utilized to better understand this process. Cell size, gene and protein expression as well as cytokine secretion were investigated. Il-6, IL-8, SerpinE1 and VEGF secretion were increased during dedifferentiation, whereas MIF-1 secretion was transiently increased. A marked decrease in expression of mature adipocyte transcripts (PPARγ2, C/EBPα, LPL and Adiponectin) was detected early in the process. In addition, some matrix remodeling transcripts (FAP, DPP4, MMP1 and TGFβ1) were rapidly and strongly up-regulated. FAP and DPP4 proteins were simultaneously induced in dedifferentiating mature adipocytes supporting a potential role for these enzymes in adipose tissue remodeling and cell plasticity. PMID:25816202

[The assessment of biological maturation for talent selection - which method can be used?].

PubMed

Müller, L; Müller, E; Hildebrandt, C; Kapelari, K; Raschner, C

2015-03-01

The biological maturity status plays an important role in sports, since it influences the performance level and the talent selection in various types of sport. More mature athletes are favorably selected for regional and national squads. Therefore, the biological maturity status should be considered during the talent selection process. In this context, the relative age effect (RAE), which exists when the relative age quarter distribution of selected sports groups shows a biased distribution with an over-representation of athletes born in the first months after the specific cut-off-date for the competition categories, represents another problem in the talent development. From an ethical point of view, discrimination of young talented kids does exist: the relatively younger athletes have little to no chance of reaching the elite level, despite their talents and efforts. The causal mechanisms behind the RAE are still unclear and have to be assessed. In this context, the biological maturation seems to be a possible influential factor for the existence of a RAE in sport, which has to be examined. Several methods for estimating the biological maturity status exist; however, they are often expensive and not practicable. Consequently, the aim of the present study was to assess the concordance of a simple, yet accurate method of estimating biological maturation (prediction equation of age at peak height velocity, APHV) of Mirwald and co-workers, and the gold standard method of estimating skeletal age (SA, the x-ray of the left wrist). In total, 75 Austrian students (40♂, 35♀) aged 10 - 13 years, were examined. Thirty of the participants (17♂, 13♀) were students of a well-known Austrian ski boarding school, and 45 (23♂, 22♀) of a non-sportive secondary modern school of the same region. The participants included in the study had not experienced a rupture of the carpal bones of the left wrist. Parents and participants were informed of the study aims, requirements and risks before providing written informed consent. The study was performed according to the Declaration of Helsinki. The study was approved by the Board for Ethical Questions in Science (Nr.: 2/2014) and the Institutional Ethics Review Boards for Human Research. For the prediction equations, the body height, the body mass and the sitting height were examined 8. The actual CA at time of measurement, and the leg length as the difference between body height and sitting height were calculated. These parameters were used to predict MO as time before or after PHV for boys and girls using the prediction equations of Mirwald et al. 19. According to Malina and Koziel 8, the participants were classified as late, on time (average) or early maturing on the basis of their APHV relative to the sample mean and standard deviation separated by sex. Participants within plus/minus the standard deviation of the mean were considered on time; participants with APHV > mean + standard deviation were classified late, while those with APHV < mean - standard deviation were classified early. An expert in pediatric endocrinology evaluated the x-rays of the left-hand wrist with the Greulich-Pyle-Method for assessing SA, the most widely used method of determining SA 24. The difference between SA and CA were calculated (= difference SA-CA). Consistent with other studies, the participants were divided into three groups according to their maturity status: on time or average maturity status was a SA within ±1 year of CA, late maturating was a SA behind CA of more than 1 year, and early maturating was a SA in advance of CA of more than 1 year 5 19 25. The most accurate method used to compare two methods of measurement is the Bland-Altman plot and the 95 % limits of agreement 26 27 28. Bland-Altman plots of the difference between difference in APHV (from the literature mean) and difference SA-CA (y-axis) and the mean of difference in APHV and difference SA-CA (x-axis) were performed. Approximately 95 % of the points in the plot should lie within the limits; then the concordance between the two methods of measurement is given 28. Additionally, intraclass correlation coefficients (ICC(3,1); two-way-mixed, total agreement) were calculated between difference in APHV and difference SA-CA. Chi²-tests were used to assess the difference in the percentage of pupils classified as on time, early or late maturing between the classifications based on the SA and on APHV, respectively. The level of significance was set at p < 0.05 and for highly significant at p < 0.01. All of the calculations were performed using PASW Statistics V.21.0. Chi²-tests did not show any significant differences (p = 0.404) in the percentage of participants classified as on time, early or late maturing between the two classifications based on SA and on APHV, respectively, neither for the total sample, nor for the two groups ski racers and non-athletes. The Bland-Altman analysis showed that more than 95 % of the points in the plot lie within the limits; consequently, there is concordance between the two methods with regard to estimating biological maturation. The ICC(3,1) statistics showed a highly significant correlation: p = 0.002, ICC (95 % CI) = 0.48 (0.13 - 0.69). The prediction equations to determine APHV seem to be a valid method of assessing the biological maturity status of youths aged 10 - 13 years. The percentage of pupils classified as on time, early or late maturing did not differ significantly between the classifications based on the two methods. Also the Bland-Altman analysis proved the concordance between the two methods. The RAE could be influenced and strengthened by the biological age in sports in which advantages in maturity parameters are important. Athletes born early in the selection year, who are also at the same time advanced in maturity, might be advantaged in the selection process. However, since the prediction equations seem to be valid, this method can be used in the future in the talent selection process in order to not disadvantage late-maturing athletes, which in turn could result in the reduction of the occurrence of the RAE in various types of sports in the future. In talent selection processes the growth spurt and the implemented changes in proportions between core and the extremities are often not considered; although it was shown that during this period, athletes showed poor performances in physical fitness. Since physical fitness is an important criterion in talent selection processes, athletes who go through their individual peak growth spurt at the time of selection have disadvantages due to the diverse proportions. As a consequence, it seems important to know the athlete's APHV in order to consider the variations in physical performance caused by developmental changes. The prediction equations to determine APHV include the leg length and sitting height in order to consider the diverse proportions between core and extremities; hence, this method seems to be accurate and should be implemented in the talent selection process. © Georg Thieme Verlag KG Stuttgart · New York.

Differential maturation of rhythmic clock gene expression during early development in medaka (Oryzias latipes).

PubMed

Cuesta, Ines H; Lahiri, Kajori; Lopez-Olmeda, Jose Fernando; Loosli, Felix; Foulkes, Nicholas S; Vallone, Daniela

2014-05-01

One key challenge for the field of chronobiology is to identify how circadian clock function emerges during early embryonic development. Teleosts such as the zebrafish are ideal models for studying circadian clock ontogeny since the entire process of development occurs ex utero in an optically transparent chorion. Medaka (Oryzias latipes) represents another powerful fish model for exploring early clock function with, like the zebrafish, many tools available for detailed genetic analysis. However, to date there have been no reports documenting circadian clock gene expression during medaka development. Here we have characterized the expression of key clock genes in various developmental stages and in adult tissues of medaka. As previously reported for other fish, light dark cycles are required for the emergence of clock gene expression rhythms in this species. While rhythmic expression of per and cry genes is detected very early during development and seems to be light driven, rhythmic clock and bmal expression appears much later around hatching time. Furthermore, the maturation of clock function seems to correlate with the appearance of rhythmic expression of these positive elements of the clock feedback loop. By accelerating development through elevated temperatures or by artificially removing the chorion, we show an earlier onset of rhythmicity in clock and bmal expression. Thus, differential maturation of key elements of the medaka clock mechanism depends on the developmental stage and the presence of the chorion.

Longitudinal Growth Curves of Brain Function Underlying Inhibitory Control through Adolescence

PubMed Central

Foran, William; Velanova, Katerina; Luna, Beatriz

2013-01-01

Neuroimaging studies suggest that developmental improvements in inhibitory control are primarily supported by changes in prefrontal executive function. However, studies are contradictory with respect to how activation in prefrontal regions changes with age, and they have yet to analyze longitudinal data using growth curve modeling, which allows characterization of dynamic processes of developmental change, individual differences in growth trajectories, and variables that predict any interindividual variability in trajectories. In this study, we present growth curves modeled from longitudinal fMRI data collected over 302 visits (across ages 9 to 26 years) from 123 human participants. Brain regions within circuits known to support motor response control, executive control, and error processing (i.e., aspects of inhibitory control) were investigated. Findings revealed distinct developmental trajectories for regions within each circuit and indicated that a hierarchical pattern of maturation of brain activation supports the gradual emergence of adult-like inhibitory control. Mean growth curves of activation in motor response control regions revealed no changes with age, although interindividual variability decreased with development, indicating equifinality with maturity. Activation in certain executive control regions decreased with age until adolescence, and variability was stable across development. Error-processing activation in the dorsal anterior cingulate cortex showed continued increases into adulthood and no significant interindividual variability across development, and was uniquely associated with task performance. These findings provide evidence that continued maturation of error-processing abilities supports the protracted development of inhibitory control over adolescence, while motor response control regions provide early-maturing foundational capacities and suggest that some executive control regions may buttress immature networks as error processing continues to mature. PMID:24227721

The Synchronization within and Interaction between the Default and Dorsal Attention Networks in Early Infancy

PubMed Central

Gilmore, John H.; Shen, Dinggang; Smith, Jeffery Keith; Zhu, Hongtu

2013-01-01

An anticorrelated interaction between the dorsal attention and the default-mode networks has been observed, although how these 2 networks establish such relationship remains elusive. Behavioral studies have reported the emergence of attention and default network–related functions and a preliminary competing relationship between them at early infancy. This study attempted to test the hypothesis—resting-state functional magnetic resonance imaging will demonstrate not only improved network synchronization of the dorsal attention and the default networks, respectively, during the first 2 years of life but also an anticorrelated network interaction pattern between the 2 networks at 1 year which will be further enhanced at 2 years old. Our results demonstrate that both networks start from an isolated region in neonates but evolve to highly synchronized networks at 1 year old. Paralleling the individual network maturation process, the anticorrelated behaviors are absent at birth but become apparent at 1 year and are further enhanced during the second year of life. Our studies elucidate not only the individual maturation process of the dorsal attention and default networks but also offer evidence that the maturation of the individual networks may be needed prior exhibiting the adult-like interaction patterns between the 2 networks. PMID:22368080

Switchgrass cultivar, yield, and nutrient removal responses to harvest timing

USDA-ARS?s Scientific Manuscript database

Finite nutrients, such as P (phosphorus) and K (potassium) are remobilized post-growing season in herbaceous feedstocks such as swichgrass (Panicum virgatum L.) as a function of environmental signaling and genotype. However, harvesting early during the maturation process may result in yield reductio...

Maturation of Executive Functioning Skills in Early Sequential Bilingualism

ERIC Educational Resources Information Center

Kalashnikova, Marina; Mattock, Karen

2014-01-01

Previous research has demonstrated that being bilingual from birth is advantageous for the development of skills of social cognition, executive functioning, and metalinguistic awareness due to bilingual children's extensive experience of processing and manipulating two linguistic systems. The present study investigated whether these cognitive…

Isolated Learners: Young Mature-Age Students, University Culture, and Desire for Academic Sociality

ERIC Educational Resources Information Center

Mallman, Mark; Lee, Helen

2017-01-01

The differentiated experiences of "young" mature-age students are under-researched and often unacknowledged in higher education literature and university policy. This article contends that, due to their age (early 20s to early 30s), many younger mature-age students feel "out of the loop" and "alienated" from…

Maturation of Black Cherry Fruits in Central Mississippi

Treesearch

F.T. Bonner

1975-01-01

Black cherry (Prunus serotina Ehrh.) in central Mississippi grew in size and weight from early May until maturity in late June. In early June, crude fat, protein-nitrogen, and calcium concentrations increased; moisture content decreased; endocarps hardened; and embryo tissues became firm. From mid-June to maturity mesocarp growth was prominent as...

Onto-phylogenetic aspect of myotomal myogenesis in Chordata.

PubMed

Kiełbówna, Leokadia; Daczewska, Małgorzata

2004-01-01

This paper presents an onto- and phylogenetic aspect of myotoamal myogenesis in Chordata. A comparative analysis of early stages of myotomal myogenesis in Chordata indicates that the myogenic process in this phylum underwent evolutionary changes. The first stage of the process is myogenesis leading to development of mononucleate mature muscle cells, the most advanced stage is formation of multinucleate muscle fibres.

The developmental dynamics of gait maturation with a focus on spatiotemporal measures.

PubMed

Kraan, C M; Tan, A H J; Cornish, K M

2017-01-01

Gait analysis is recognised as a powerful clinical tool for studying relationships between motor control and brain function. By drawing on the literature investigating gait in individuals with neurological disorders, this review provides insight into the neural processes that contribute to and regulate specific spatiotemporal sub-components of gait and how they may mature across early to late childhood. This review also discusses the roles of changing anthropomorphic characteristics, and maturing sensory and higher-order cognitive processes in differentiating the developmental trajectories of the sub-components of gait. Importantly, although studies have shown that cognitive-gait interference is larger in children compared to adults, the contributing neurocognitive mechanisms may vary across age groups who have different types of attentional or cognitive vulnerabilities. These findings have implications for current models of gait maturation by highlighting the need for a dynamic model that focuses on the integration of various factors that contribute to gait though experience and practice. This is essential to elucidating why gait and other motor deficits are often contiguous with cognitive neurodevelopmental disorders. Copyright © 2016. Published by Elsevier B.V.

Early natural stimulation through environmental enrichment accelerates neuronal development in the mouse dentate gyrus.

PubMed

Liu, Na; He, Shan; Yu, Xiang

2012-01-01

The dentate gyrus is the primary afferent into the hippocampal formation, with important functions in learning and memory. Granule cells, the principle neuronal type in the dentate gyrus, are mostly formed postnatally, in a process that continues into adulthood. External stimuli, including environmental enrichment, voluntary exercise and learning, have been shown to significantly accelerate the generation and maturation of dentate granule cells in adult rodents. Whether, and to what extent, such environmental stimuli regulate the development and maturation of dentate granule cells during early postnatal development is largely unknown. Furthermore, whether natural stimuli affect the synaptic properties of granule cells had been investigated neither in newborn neurons of the adult nor during early development. To examine the effect of natural sensory stimulation on the dentate gyrus, we reared newborn mice in an enriched environment (EE). Using immunohistochemistry, we showed that dentate granule cells from EE-reared mice exhibited earlier morphological maturation, manifested as faster peaking of doublecortin expression and elevated expression of mature neuronal markers (including NeuN, calbindin and MAP2) at the end of the second postnatal week. Also at the end of the second postnatal week, we found increased density of dendritic spines across the entire dentate gyrus, together with elevated levels of postsynaptic scaffold (post-synaptic density 95) and receptor proteins (GluR2 and GABA(A)Rγ2) of excitatory and inhibitory synapses. Furthermore, dentate granule cells of P14 EE-reared mice had lower input resistances and increased glutamatergic and GABAergic synaptic inputs. Together, our results demonstrate that EE-rearing promotes morphological and electrophysiological maturation of dentate granule cells, underscoring the importance of natural environmental stimulation on development of the dentate gyrus.

High-density genetic linkage map construction by F2 populations and QTL analysis of early-maturity traits in upland cotton (Gossypium hirsutum L.).

PubMed

Li, Libei; Zhao, Shuqi; Su, Junji; Fan, Shuli; Pang, Chaoyou; Wei, Hengling; Wang, Hantao; Gu, Lijiao; Zhang, Chi; Liu, Guoyuan; Yu, Dingwei; Liu, Qibao; Zhang, Xianlong; Yu, Shuxun

2017-01-01

Due to China's rapidly increasing population, the total arable land area has dramatically decreased; as a consequence, the competition for farming land allocated for grain and cotton production has become fierce. Therefore, to overcome the existing contradiction between cotton grain and fiber production and the limited farming land, development of early-maturing cultivars is necessary. In this research, a high-density linkage map of upland cotton was constructed using genotyping by sequencing (GBS) to discover single nucleotide polymorphism (SNP) markers associated with early maturity in 170 F2 individuals derived from a cross between LU28 and ZHONG213. The high-density genetic map, which was composed of 3978 SNP markers across the 26 cotton chromosomes, spanned 2480 cM with an average genetic distance of 0.62 cM. Collinearity analysis showed that the genetic map was of high quality and accurate and agreed well with the Gossypium hirsutum reference genome. Based on this high-density linkage map, QTL analysis was performed on cotton early-maturity traits, including FT, FBP, WGP, NFFB, HNFFB and PH. A total 47 QTLs for the six traits were detected; each of these QTLs explained between 2.61% and 32.57% of the observed phenotypic variation. A major region controlling early-maturity traits in Gossypium hirsutum was identified for FT, FBP, WGP, NFFB and HNFFB on chromosome D03. QTL analyses revealed that phenotypic variation explained (PVE) ranged from 10.42% to 32.57%. Two potential candidate genes, Gh_D03G0885 and Gh_D03G0922, were predicted in a stable QTL region and had higher expression levels in the early-maturity variety ZHONG213 than in the late-maturity variety LU28. However, further evidence is required for functional validation. This study could provide useful information for the dissection of early-maturity traits and guide valuable genetic loci for molecular-assisted selection (MAS) in cotton breeding.

High-density genetic linkage map construction by F2 populations and QTL analysis of early-maturity traits in upland cotton (Gossypium hirsutum L.)

PubMed Central

Li, Libei; Zhao, Shuqi; Su, Junji; Fan, Shuli; Pang, Chaoyou; Wei, Hengling; Wang, Hantao; Gu, Lijiao; Zhang, Chi; Liu, Guoyuan; Yu, Dingwei; Liu, Qibao; Zhang, Xianlong

2017-01-01

Due to China’s rapidly increasing population, the total arable land area has dramatically decreased; as a consequence, the competition for farming land allocated for grain and cotton production has become fierce. Therefore, to overcome the existing contradiction between cotton grain and fiber production and the limited farming land, development of early-maturing cultivars is necessary. In this research, a high-density linkage map of upland cotton was constructed using genotyping by sequencing (GBS) to discover single nucleotide polymorphism (SNP) markers associated with early maturity in 170 F2 individuals derived from a cross between LU28 and ZHONG213. The high-density genetic map, which was composed of 3978 SNP markers across the 26 cotton chromosomes, spanned 2480 cM with an average genetic distance of 0.62 cM. Collinearity analysis showed that the genetic map was of high quality and accurate and agreed well with the Gossypium hirsutum reference genome. Based on this high-density linkage map, QTL analysis was performed on cotton early-maturity traits, including FT, FBP, WGP, NFFB, HNFFB and PH. A total 47 QTLs for the six traits were detected; each of these QTLs explained between 2.61% and 32.57% of the observed phenotypic variation. A major region controlling early-maturity traits in Gossypium hirsutum was identified for FT, FBP, WGP, NFFB and HNFFB on chromosome D03. QTL analyses revealed that phenotypic variation explained (PVE) ranged from 10.42% to 32.57%. Two potential candidate genes, Gh_D03G0885 and Gh_D03G0922, were predicted in a stable QTL region and had higher expression levels in the early-maturity variety ZHONG213 than in the late-maturity variety LU28. However, further evidence is required for functional validation. This study could provide useful information for the dissection of early-maturity traits and guide valuable genetic loci for molecular-assisted selection (MAS) in cotton breeding. PMID:28809947

A mature Bosch CO2 reduction technology. [for long-duration space missions

NASA Technical Reports Server (NTRS)

King, C. D.; Holmes, R. F.

1976-01-01

The reduction of CO2 is one of the steps in closing the oxygen loop for long-duration manned space missions. Several units utilizing the Bosch process, which catalytically reduces CO2 with hydrogen, have been built and operated during the past decade. Each contributed substantial information affecting subsequent designs. Early challenges were primarily concerned with carbon control, materials durability, and reliability of reaction initiation. These were followed by concern about power consumption, expendable weight, volume, and process rate control. Suitable materials and techniques for carbon containment and process reliability have been demonstrated. Power requirements have been reduced by almost an order of magnitude. Methods for significant reductions in expendable weight and volume have been developed. The technology is at a state of maturity directly applicable to designs for space missions.

Sexual maturation in kokanee Oncorhynchus nerka

USGS Publications Warehouse

Patterson, S.D.; Scarnecchia, D.L.; Congleton, J.L.

2008-01-01

We used observational and experimental approaches to obtain information on factors affecting the timing of maturation of kokanee Oncorhynchus nerka, a semelparous, landlocked salmon. Gonadal staging criteria were developed and applied to three kokanee populations in Idaho lakes and reservoirs. Testes were classified into three stages: immature (stage one, S1), maturing (S2), and mature (S3). Ovaries were classified into eight stages: immature (S1-S3), transitional (stage S4), maturing (S5-S7), and mature (S8). Males entered the maturing stage (S2) in February through April of the spawning year. Females entered maturing stage (S5) as early as July of the year before the spawning year, and as late as March of the spawning year. Three hatchery experiments demonstrated that attainment of a larger body size 10 to 16 months before spawning increased the likelihood of initiation of maturation in both sexes. No gonads in a state of regression were observed. A gonadosomatic index above 0.1 by early July was a good indicator of a maturing male, and a gonadosomatic index above 1.0 by early July was a good indicator of a maturing female. Instantaneous growth rates were not good predictors of maturation, but attaining a size threshold of 18 to 19 cm in the fall was a good predictor of maturation the following year. This improved knowledge of kokanee maturation will permit more effectively management of the species for age, growth and size at maturity as well as for contributions to fisheries. ?? 2008 by the Northwest Scientific Association. All rights reserved.

Identification of soybean genotypes adaptive to tropical area and suitable for industry

NASA Astrophysics Data System (ADS)

Adie, M. M.; Krisnawati, A.

2018-01-01

Soybeans in Indonesia are mostly used for raw material of tempeh industry. This study aims to identify 150 soybean genotypes for their suitability for raw materials of tempeh and adaptability to be developed in tropical area of Indonesia. The research material consisted of 150 soybean genotypes. The field research was conducted in Malang from February to May 2016, using a randomized block design with two replicates. The identification of 150 soybean genotypes showed 30.67% of super early maturity (<75 days), 50% of early maturity (76 - 79 days), and 19.33% were medium maturity (80 - 90 days). In the group of super early maturity, 11 genotypes were yielded between 3.01 - 3.69 t/ha and the 100 seed weight ranged from 15.27 - 20.18 g. In the early maturity group, there were 23 genotypes with seed yields between 3.01 - 3.66 t/ha, and the 100 seed weight ranged from 13.90 - 20.23 g. In Indonesia, tempeh industry requires soybeans with large seed size. In this research, G511H/Anj//Anj////Anjs-8-5 was suitable to be developed in Indonesia’s tropical climate and also preferred by industry for tempeh raw material due to its high yield, super early days to maturity, and large seed size.

Explaining Why Early-Maturing Girls Are More Exposed to Sexual Harassment in Early Adolescence

ERIC Educational Resources Information Center

Skoog, Therése; Bayram Özdemir, Sevgi

2016-01-01

In this study, we tested two competing explanations of the previously established link between early female puberty and sexual harassment in early adolescence. The sample included 680 seventh-grade Swedish girls (M[subscript age] = 13.40, SD = 0.53). Findings revealed that looking more sexually mature and being sexually active mediated the link…

The presence of acylated ghrelin during in vitro maturation of bovine oocytes induces cumulus cell DNA damage and apoptosis, and impairs early embryo development.

PubMed

Sirini, Matias A; Anchordoquy, Juan Mateo; Anchordoquy, Juan Patricio; Pascua, Ana M; Nikoloff, Noelia; Carranza, Ana; Relling, Alejandro E; Furnus, Cecilia C

2017-10-01

The aim of this study was to investigate the effects of acylated ghrelin supplementation during in vitro maturation (IVM) of bovine oocytes. IVM medium was supplemented with 20, 40 or 60 pM acylated ghrelin concentrations. Cumulus expansion area and oocyte nuclear maturation were studied as maturation parameters. Cumulus-oocyte complexes (COC) were assessed with the comet, apoptosis and viability assays. The in vitro effects of acylated ghrelin on embryo developmental capacity and embryo quality were also evaluated. Results demonstrated that acylated ghrelin did not affect oocyte nuclear maturation and cumulus expansion area. However, it induced cumulus cell (CC) death, apoptosis and DNA damage. The damage increased as a function of the concentration employed. Additionally, the percentages of blastocyst yield, hatching and embryo quality decreased with all acylated ghrelin concentrations tested. Our study highlights the importance of acylated ghrelin in bovine reproduction, suggesting that this metabolic hormone could function as a signal that prevents the progress to reproductive processes.

Exploring Work and Development Options to Reduce Early Labour Force Exit of Mature Aged Australians

ERIC Educational Resources Information Center

Pillay, Hitendra; Kelly, Kathy; Tones, Megan

2008-01-01

Early labour force exit is a significant challenge associated with the ageing workforce in Australia and many other developed countries. A reduction and increased flexibility of work hours has been suggested to improve labour force participation of the mature aged cohort. However, little is known about mature aged workers' aspirations for…

Bicarbonate Transport During Enamel Maturation.

PubMed

Yin, Kaifeng; Paine, Michael L

2017-11-01

Amelogenesis (tooth enamel formation) is a biomineralization process consisting primarily of two stages (secretory stage and maturation stage) with unique features. During the secretory stage, the inner epithelium of the enamel organ (i.e., the ameloblast cells) synthesizes and secretes enamel matrix proteins (EMPs) into the enamel space. The protein-rich enamel matrix forms a highly organized architecture in a pH-neutral microenvironment. As amelogenesis transitions to maturation stage, EMPs are degraded and internalized by ameloblasts through endosomal-lysosomal pathways. Enamel crystallite formation is initiated early in the secretory stage, however, during maturation stage the more rapid deposition of calcium and phosphate into the enamel space results in a rapid expansion of crystallite length and mineral volume. During maturation-stage amelogenesis, the pH value of enamel varies considerably from slightly above neutral to acidic. Extracellular acid-base balance during enamel maturation is tightly controlled by ameloblast-mediated regulatory networks, which include significant synthesis and movement of bicarbonate ions from both the enamel papillary layer cells and ameloblasts. In this review we summarize the carbonic anhydrases and the carbonate transporters/exchangers involved in pH regulation in maturation-stage amelogenesis. Proteins that have been shown to be instrumental in this process include CA2, CA6, CFTR, AE2, NBCe1, SLC26A1/SAT1, SLC26A3/DRA, SLC26A4/PDS, SLC26A6/PAT1, and SLC26A7/SUT2. In addition, we discuss the association of miRNA regulation with bicarbonate transport in tooth enamel formation.

Reconstructing life history of hominids and humans.

PubMed

Crews, Douglas E; Gerber, Linda M

2003-06-01

Aspects of life history, such as processes and timing of development, age at maturation, and life span are consistently associated with one another across the animal kingdom. Species that develop rapidly tend to mature and reproduce early, have many offspring, and exhibit shorter life spans (r-selection) than those that develop slowly, have extended periods of premature growth, mature later in life, reproduce later and less frequently, have few offspring and/or single births, and exhibit extended life spans (K-selection). In general, primates are among the most K-selected of species. A suite of highly derived life history traits characterizes humans. Among these are physically immature neonates, slowed somatic development both in utero and post-natally, late attainment of reproductive maturity and first birth, and extended post-mature survival. Exactly when, why, and through what types of evolutionary interactions this suite arose is currently the subject of much conjecture and debate. Humankind's biocultural adaptations have helped to structure human life history evolution in unique ways not seen in other animal species. Among all species, life history traits may respond rapidly to alterations in selective pressures through hormonal processes. Selective pressures on life history likely varied widely among hominids and humans over their evolutionary history. This suggests that current patterns of human growth, development, maturation, reproduction, and post-mature survival may be of recent genesis, rather then long-standing adaptations. Thus, life history patterns observed among contemporary human and chimpanzee populations may provide little insight to those that existed earlier in hominid/human evolution.

The role of early maturation, perceived popularity, and rumors in the emergence of internalizing symptoms among adolescent girls.

PubMed

Reynolds, Bridget M; Juvonen, Jaana

2011-11-01

Despite the widely reported link between early pubertal timing and internalizing symptoms among girls, less is known about the peer reputation of earlier maturing girls. The current study assesses whether early maturation is associated with perceived popularity and/or rumors, and whether these reputational factors help account for earlier maturing girls' vulnerability to emotional distress. Drawing on three waves of data collected from an ethnically diverse sample of middle school girls (n = 912), hierarchical multiple regression analyses revealed that more advanced development at the start of middle school predicted peer- and teacher-reported popularity as well as increased risk of being targeted for rumors. Mediation analyses suggested that popularity among boys can put earlier developing girls at risk for rumors. Finally, rumors acted as a partial mechanism through which early maturation was associated with subsequent internalizing symptoms. Knowledge of the peer mechanisms putting earlier developing girls at risk for psychosocial maladjustment can inform intervention and prevention efforts aimed at improving adolescent well-being.

Association of sexual maturation with excess body weight and height in children and adolescents

PubMed Central

2014-01-01

Background Studies addressing the influence of early sexual maturation on the excess of body weight and height of children and adolescents are scarce. The aim of the study was to analyze the association of sexual maturation with excess body weight and height in children and adolescents. Methods This was a cross-sectional study performed in Florianópolis city, Brazil, in 2007, with 2339 school children, aged 8–14 years (1107 males). Selection was based on a probabilistic, cluster-stratified sampling technique. School children were classified according to the presence of excess body weight, using sex- and age-specific body mass index (BMI) cutoff points. Z-scores were calculated from height and BMI data. Sexual maturation was self-assessed according to Tanner stages of development. Subjects were ranked based on tertiles of sexual maturation (early, normal and late) for each stage of development. Poisson and linear regression models were used. Results Compared to the reference group (normal sexual maturation), early maturing females had higher prevalence of excess weight (adjusted prevalence ratio: 1.70; 95% CI: 1.24 to 2.33) and increased height-for-age (adjusted β: 0.37; 95% CI: 0.14 to 0.59), while late maturing females had lower prevalence of excess weight (adjusted prevalence ratio: 0.57; 95% CI: 0.37 to 0.87) and decreased height-for-age (adjusted β: −0.38; 95% CI: −0.56 to −0.20). In males, early and late sexual maturation were associated with increased (adjusted β: 0.37; 95% CI: 0.14 to 0.59) and decreased (adjusted β: −0.38; 95% CI: −0.56 to −0.20) height-for-age, respectively. Conclusion Early sexual maturation is associated with excess body weight in females and with greater height-for-age in both sexes. PMID:24625111

Ion currents involved in oocyte maturation, fertilization and early developmental stages of the ascidian Ciona intestinalis.

PubMed

Tosti, Elisabetta; Gallo, Alessandra; Silvestre, Francesco

2011-01-01

Electrophysiological techniques were used to study the role of ion currents in the ascidian Ciona intestinalis oocyte plasma membrane during different stages of growth, meiosis, fertilization and early development. Three stages of immature oocytes were discriminated in the ovary, with the germinal vesicle showing specific different features of growth and maturation. Stage-A (pre-vitellogenic) oocytes exhibited the highest L-type calcium current activity and were incompetent for meiosis resumption. Stage-B (vitellogenic) oocytes showed a progressive disappearance of calcium currents and the first appearance of sodium currents that remained high during the maturation process, up to the post-vitellogenic stage-C oocytes. The latter had acquired meiotic competence, undergoing spontaneous in vitro maturation and interacting with the spermatozoon. However, fertilized oocytes did not produce normal larvae, suggesting that cytoplasmic maturation may affect embryo development. In mature oocytes at the metaphase I stage, sodium currents were present and remained high up to the zygote stage. Oocytes fertilized in the absence of sodium showed significant reduction of the fertilization current amplitude and high development of anomalous "rosette" embryos. Current amplitudes became negligible in embryos at the 2- and 4-cell stage, whereas resumption of all the current activities occurred at the 8-cell embryo. Taken together, these results suggest: (i) an involvement of L-type calcium currents in initial oocyte meiotic progression and growth; (ii) a role of sodium currents at fertilization; (iii) a role of the fertilization current in ensuring normal embryo development. Copyright © 2011 Wiley Periodicals, Inc.

The Challenge of Sexual Maturation in Early Adolescence.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Counseling and Personnel Services, Ann Arbor, MI.

This fifth chapter in "The Challenge of Counseling in Middle Schools" looks at the issue of sexual maturation in early adolescence via four articles. "The Counselor's Impact on Middle-Grade Students," by Hershel Thornburg, examines physical, intellectual, and social developmental tasks of early adolescence. "Contraceptive and Sexuality Knowledge…

Bovine oocytes and early embryos express Staufen and ELAVL RNA-binding proteins.

PubMed

Calder, M D; Madan, P; Watson, A J

2008-05-01

RNA-binding proteins (RBP) influence RNA editing, localization, stability and translation and may contribute to oocyte developmental competence by regulating the stability and turnover of oogenetic mRNAs. The expression of Staufen 1 and 2 and ELAVL1, ELAVL2 RNA-binding proteins during cow early development was characterized. Cumulus-oocyte complexes were collected from slaughterhouse ovaries, matured, inseminated and subjected to embryo culture in vitro. Oocyte or preimplantation embryo pools were processed for RT-PCR and whole-mount immunofluorescence analysis of mRNA expression and protein distribution. STAU1 and STAU2 and ELAVL1 mRNAs and proteins were detected throughout cow preimplantation development from the germinal vesicle (GV) oocyte to the blastocyst stage. ELAVL2 mRNAs were detectable from the GV to the morula stage, whereas ELAVL2 protein was in all stages examined and localized to both cytoplasm and nuclei. The findings provide a foundation for investigating the role of RBPs during mammalian oocyte maturation and early embryogenesis.

Mapping-by-Sequencing Identifies HvPHYTOCHROME C as a Candidate Gene for the early maturity 5 Locus Modulating the Circadian Clock and Photoperiodic Flowering in Barley

PubMed Central

Pankin, Artem; Campoli, Chiara; Dong, Xue; Kilian, Benjamin; Sharma, Rajiv; Himmelbach, Axel; Saini, Reena; Davis, Seth J; Stein, Nils; Schneeberger, Korbinian; von Korff, Maria

2014-01-01

Phytochromes play an important role in light signaling and photoperiodic control of flowering time in plants. Here we propose that the red/far-red light photoreceptor HvPHYTOCHROME C (HvPHYC), carrying a mutation in a conserved region of the GAF domain, is a candidate underlying the early maturity 5 locus in barley (Hordeum vulgare L.). We fine mapped the gene using a mapping-by-sequencing approach applied on the whole-exome capture data from bulked early flowering segregants derived from a backcross of the Bowman(eam5) introgression line. We demonstrate that eam5 disrupts circadian expression of clock genes. Moreover, it interacts with the major photoperiod response gene Ppd-H1 to accelerate flowering under noninductive short days. Our results suggest that HvPHYC participates in transmission of light signals to the circadian clock and thus modulates light-dependent processes such as photoperiodic regulation of flowering. PMID:24996910

Olfactory marker protein is critical for functional maturation of olfactory sensory neurons and development of mother preference

PubMed Central

Lee, Anderson C.; He, Jiwei; Ma, Minghong

2011-01-01

Survival of many altricial animals critically depends on the sense of smell. Curiously, the olfactory system is rather immature at birth and undergoes a maturation process, which is poorly understood. Using patch clamp technique on mouse olfactory sensory neurons (OSNs) with a defined odorant receptor (OR), we demonstrate that OSNs exhibit functional maturation during the first month of postnatal life by developing faster response kinetics, higher sensitivity, and most intriguingly, higher selectivity. OSNs expressing the receptor MOR23 are relatively broadly tuned in neonates and become selective detectors for the cognate odorant within two weeks. Remarkably, these changes are prevented by genetic ablation of olfactory marker protein (OMP), which is exclusively expressed in mature OSNs. Biochemical and pharmacological evidence supports that alteration in odorant-induced phosphorylation of signaling proteins underlie some of the OMP−/− phenotypes. Furthermore, in a novel behavioral assay in which the mouse pups are given a choice between the biological mother and another unfamiliar lactating female, wild-type pups prefer the biological mother, while OMP knockout pups fail to show preference. These results reveal that OSNs undergo an OMP-dependant functional maturation process that coincides with early development of the smell function, which is essential for pups to form preference for their mother. PMID:21414919

Maturity Group Classification and Maturity Locus Genotyping of Early-Maturing Soybean Varieties from High-Latitude Cold Regions

PubMed Central

Lu, Wencheng; Hou, Wensheng; Sun, Shi; Yan, Hongrui; Han, Tianfu

2014-01-01

Background With the migration of human beings, advances of agricultural sciences, evolution of planting patterns and global warming, soybeans have expanded to both tropical and high-latitude cold regions (HCRs). Unlike other regions, HCRs have much more significant and diverse photoperiods and temperature conditions over seasons or across latitudes, and HCR soybeans released there show rich diversity in maturity traits. However, HCR soybeans have not been as well classified into maturity groups (MGs) as other places. Therefore, it is necessary to identify MGs in HCRs and to genotype the maturity loci. Methods Local varieties were collected from the northern part of Northeast China and the far-eastern region of Russia. Maturity group reference (MGR) soybeans of MGs MG000, MG00, and MG0 were used as references during field experiments. Both local varieties and MGR soybeans were planted for two years (2010-2011) in Heihe (N 50°15′, E 127°27′, H 168.5 m), China. The days to VE (emergence), R1 (beginning bloom) and R7 (beginning maturity) were recorded and statistically analyzed. Furthermore, some varieties were further genotyped at four molecularly-identified maturity loci E1, E2, E3 and E4. Results The HCR varieties were classified into MG0 or even more early-maturing. In Heihe, some varieties matured much earlier than MG000, which is the most early-maturing known MG, and clustered into a separate group. We designated the group as MG0000, following the convention of MGs. HCR soybeans had relatively stable days to beginning bloom from emergence. The HCR varieties diversified into genotypes of E1, E2, E3 and E4. These loci had different effects on maturity. Conclusion HCRs diversify early-maturing MGs of soybean. MG0000, a new MG that matures much earlier than known MGs, was developed. HCR soybean breeding should focus more on shortening post-flowering reproductive growth. E1, E2, E3, and E4 function differentially. PMID:24740097

Biogeochemical drivers of microbial community convergence across actively retreating glaciers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castle, Sarah C.; Nemergut, Diana R.; Grandy, A. Stuart

The ecological processes that influence biogeographical patterns of microorganisms are actively debated. To investigate how such patterns emerge during ecosystem succession, we examined the biogeochemical drivers of bacterial community assembly in soils over two environmentally distinct, recently deglaciated chronosequences separated by a distance of more than 1,300 kilometers. Our results show that despite different geographic, climatic, and soil chemical and physical characteristics at the two sites, soil bacterial community structure and decomposer function converged during plant succession. In a comparative analysis, we found that microbial communities in early succession soils were compositionally distinct from a group of diverse, mature forestmore » soils, but that the differences between successional soils and mature soils decreased from early to late stages of succession. Differences in bacterial community composition across glacial sites were largely explained by pH. However, successional patterns and community convergence across sites were more consistently related to soil organic carbon and organic matter chemistry, which appeared to be tightly coupled with bacterial community structure across both young and mature soils.« less

Maturational differences in physical self- perceptions and the relationship with physical activity in early adolescent girls.

PubMed

Niven, Alisa G; Fawkner, Samantha G; Knowles, Anne-Marie; Stephenson, Claire

2007-11-01

This cross-sectional study examined the relationship between physical self-perceptions (PSPs), maturation, and physical activity and compared the strength of the relationships of biological and chronological age with PSPs in early adolescent girls (N = 208; mean age = 11.83 +/- 0.39 years). Participants completed the Physical Activity Questionnaire for Older Children, the Children's Physical Self-Perception Profile, and the Pubertal Development Scale. Results indicated that PSPs were significantly and moderately correlated with physical activity. There were no differences in physical activity between maturation stages. Girls who were in the early stages of maturation had significantly more positive perceptions of body attractiveness and physical self-worth than girls in the mid stages of maturation. There was no evidence of a relationship between PSPs and chronological age. This study provided further support for the relationship between PSPs and physical activity and the relationship between maturation and aspects of PSPs. In this age group, maturation does not appear to be related to physical activity or the PSPs most strongly influential on physical activity behavior.

Accounting for Change in Declarative Memory: A Cognitive Neuroscience Perspective

ERIC Educational Resources Information Center

Richmond, Jenny; Nelson, Charles A.

2007-01-01

The medial temporal lobe memory system matures relatively early and supports rudimentary declarative memory in young infants. There is considerable development, however, in the memory processes that underlie declarative memory performance during infancy. Here we consider age-related changes in encoding, retention, and retrieval in the context of…

[Local injection of exogenous nerve growth factor improves early bone maturation of implants].

PubMed

Yao, Yang; Du, Yu; Gu, Xia; Guang, Meng-Kai; Huang, Bo; Gong, Ping

2018-04-01

To investigate the effects of nerve growth factor (NGF) in the osteogenic action of implants and the maturation and reconstruction changes in bone tissues in the early stage of osseointegration. The mouse implant model was established by placing titanium in the femoral head of the mouse and locally injecting NGF in the implant zone. On 1, 2 and 4 weeks after operation, stain samples were collected from animals using hematoxylin-eosin (HE) staining and Masson staining. The effect of NGF on the bone maturation was compared at different time points of early stage osseointegration. The results of HE and Masson staining indicated that the local injection of external NGF can up-regulate bone mass, amount of bone trabecula, and bone maturity in the mouse model. The mature bone rate in treatment group of 1 week and 4 weeks after operation were significantly higher than those in the control group (P<0.05). NGF can shorten the period of bone maturation.

[Pubertal growth of 1,453 healthy children according to age at pubertal growth spurt onset. The Barcelona longitudinal growth study].

PubMed

Carrascosa, Antonio; Yeste, Diego; Moreno-Galdó, Antonio; Gussinyé, Miquel; Ferrández, Ángel; Clemente, María; Fernández-Cancio, Mónica

2018-02-20

Pubertal growth pattern differs according to age at pubertal growth spurt onset which occurs over a five years period (girls: 8-13 years, boys: 10-15 years). The need for more than one pubertal reference pattern has been proposed. We aimed to obtain five 1-year-age-interval pubertal patterns. Longitudinal (6 years of age-adult height) growth study of 1,453 healthy children to evaluate height-for-age, growth velocity-for-age and weight-for-age values. According to age at pubertal growth spurt onset girls were considered: very-early matures (8-9 years, n=119), early matures (9-10 years, n=157), intermediate matures (10-11 years, n=238), late matures (11-12 years, n=127) and very-late matures (12-13 years, n=102), and boys: very-early matures (10-11 years, n=110), early matures (11-12 years, n=139), intermediate matures (12-13 years, n=225), late matures (13-14 years, n=133) and very-late matures (14-15 years, n=103). Age at menarche and growth up to adult height were recorded. In both sexes, statistically-significant (P<.0001) and clinically-pertinent differences in pubertal growth pattern (mean height-for-age, mean growth velocity-for-age and mean pubertal height gain, values) were found among the five pubertal maturity groups and between each group and the whole population, despite similar adult height values. The same occurred for age at menarche and growth from menarche to adult height (P<.05). In both sexes, pubertal growth spurt onset is a critical milestone determining pubertal growth and sexual development. The contribution of our data to better clinical evaluation of growth according to the pubertal maturity tempo of each child will obviate the mistakes made when only one pubertal growth reference is used. Copyright © 2018. Publicado por Elsevier España, S.L.U.

Adolescent pregnancy: contributing factors, consequences, treatment, and plausible solutions.

PubMed

Black, C; DeBlassie, R R

1985-01-01

Adolescence, although not always necessarily a period of extreme stress, is a time of profound physical changes which increase the adolescent's awareness of and interest in sexual behavior. This issue of sexuality, which begins in early adolescence, creates new challenges to personal and gender identity formation as the person matures. Sexual maturation is a three-fold process, requiring growth in understanding of oneself as a sexual being, in the ability to handle interpersonal relationships effectively, and in the capacity to plan behavior in view of future outcomes and present problems. A current concern is that today's adolescents, including early adolescents, may be making important life choices such as parenthood before they are developmentally ready for such roles (Chilman, 1980). This paper deals with pregnancy in adolescents and modes of responding to this phenomenon by those in the counseling and other helping professions.

Agile: From Software to Mission Systems

NASA Technical Reports Server (NTRS)

Trimble, Jay; Shirley, Mark; Hobart, Sarah

2017-01-01

To maximize efficiency and flexibility in Mission Operations System (MOS) design, we are evolving principles from agile and lean methods for software, to the complete mission system. This allows for reduced operational risk at reduced cost, and achieves a more effective design through early integration of operations into mission system engineering and flight system design. The core principles are assessment of capability through demonstration, risk reduction through targeted experiments, early test and deployment, and maturation of processes and tools through use.

Endocrine Disruption and Human Prostate Cancer

DTIC Science & Technology

2008-03-01

decades in men . Briefly we use rodent stroma to create a niche in which human stem cells are directed to become human prostatic epithelia. Task 1 sought to...we used our model system to study human prostate development and maturation over 8-12 weeks, comparable to the process that takes decades in men ...was 100%. The early onset of prostatitis, is comparable to the onset of non-bacterial early-onset prostatitis in younger men , and implicates the EDC

Increasing maturity of kerogen type II reflected by alkylbenzene distribution from pyrolysis-gas chromatography-mass spectrometry

USGS Publications Warehouse

Lis, G.P.; Mastalerz, Maria; Schimmelmann, A.

2008-01-01

A series of Late Devonian to Early Mississippian type II kerogens with vitrinite reflectance values Ro 0.29-2.41% were analyzed using py-GC-MS. In addition, a low maturity kerogen with Ro 0.44% was separated into fractions via density gradient centrifugation, followed by py-GC-MS of the alginite and amorphinite maceral concentrates. Alkylbenzenes and n-alk-1-ene/n-alkane doublets represented the main compound classes identified in all pyrolysates. The pyrolysate from alginite featured 1,2,4-trimethylbenzene and toluene as the two most prominent alkylbenzenes. In contrast, alkylbenzenes in pyrolysates from amorphinite and low maturity bulk kerogens with Ro 0.29-0.63% were dominated by 1,2,3,4-tetramethylbenzene. With increasing thermal maturity, pyrolysates were increasingly dominated by (i) alkylbenzenes with fewer methyl groups, namely by tri- and dimethylbenzenes at medium maturity (Ro 0.69-1.19%), and (ii) by toluene at higher maturity (Ro 1.30-2.41%). With increasing maturity of kerogen type II, the decreasing abundance of highly methyl-substituted alkylbenzenes and the parallel increase in less methyl-substituted alkylbenzenes in flash pyrolysates suggest that demethylation is an important chemical process in the thermal maturation of kerogen type II. ?? 2008 Elsevier Ltd. All rights reserved.

The scientific foundations and associated injury risks of early soccer specialisation.

PubMed

Read, Paul J; Oliver, Jon L; De Ste Croix, Mark B A; Myer, Gregory D; Lloyd, Rhodri S

2016-12-01

Early specialisation is characterised by formal participation in a single sport at the exclusion of others. Limited data are available to support this approach in the development of soccer players who attain elite status later in life. Of growing concern is the associated increased risk of injury and suggestions that single sport specialisation is a risk factor independent of age, growth, biological maturation and training volumes. In the United Kingdom, elite soccer organisations have recently adopted an early sport specialisation approach following the introduction of the Elite Player Performance Plan. A key tenet of this programme is increased opportunities for training through a marked rise in the specified on-pitch hours per week. The accumulation of high training hours may be less of a relevant marker for success, and the impact of such a significant increase in training volume for young athletes who are experiencing a range of growth and maturational processes is currently unknown. This critical commentary includes an evidence-based discussion of the effectiveness of early sport specialisation and the potential injury risks associated with such programmes placing a specific focus on elite male youth soccer players. Available data indicate that modifications to the existing Elite Player Performance Plan framework could enhance players' development and reduce injury risk. Proposed alterations include reduced volume of soccer-specific training at key stages of growth and maturation and guidelines for the provision of a greater variety of physical activities that are integrated within other programme components.

The scientific foundations and associated injury risks of early soccer specialisation

PubMed Central

Read, Paul J.; Oliver, Jon L.; De Ste Croix, Mark B. A.; Myer, Gregory D.; Lloyd, Rhodri S.

2017-01-01

Early specialisation is characterised by formal participation in a single sport at the exclusion of others. Limited data are available to support this approach in the development of soccer players who attain elite status later in life. Of growing concern is the associated increased risk of injury and suggestions that single sport specialisation is a risk factor independent of age, growth, biological maturation and training volumes. In the United Kingdom, elite soccer organisations have recently adopted an early sport specialisation approach following the introduction of the Elite Player Performance Plan. A key tenet of this programme is increased opportunities for training through a marked rise in the specified on-pitch hours per week. The accumulation of high training hours may be less of a relevant marker for success, and the impact of such a significant increase in training volume for young athletes who are experiencing a range of growth and maturational processes is currently unknown. This critical commentary includes an evidence-based discussion of the effectiveness of early sport specialisation and the potential injury risks associated with such programmes placing a specific focus on elite male youth soccer players. Available data indicate that modifications to the existing Elite Player Performance Plan framework could enhance players’ development and reduce injury risk. Proposed alterations include reduced volume of soccer-specific training at key stages of growth and maturation and guidelines for the provision of a greater variety of physical activities that are integrated within other programme components. PMID:27120711

Dopamine-dependent periadolescent maturation of corticostriatal functional connectivity in mouse.

PubMed

Galiñanes, Gregorio L; Taravini, Irene R E; Murer, M Gustavo

2009-02-25

Altered corticostriatal information processing associated with early dopamine systems dysfunction may contribute to attention deficit/hyperactivity disorder (ADHD). Mice with neonatal dopamine-depleting lesions exhibit hyperactivity that wanes after puberty and is reduced by psychostimulants, reminiscent of some aspects of ADHD. To assess whether the maturation of corticostriatal functional connectivity is altered by early dopamine depletion, we examined preadolescent and postadolescent urethane-anesthetized mice with or without dopamine-depleting lesions. Specifically, we assessed (1) synchronization between striatal neuron discharges and oscillations in frontal cortex field potentials and (2) striatal neuron responses to frontal cortex stimulation. In adult control mice striatal neurons were less spontaneously active, less responsive to cortical stimulation, and more temporally tuned to cortical rhythms than in infants. Striatal neurons from hyperlocomotor mice required more current to respond to cortical input and were less phase locked to ongoing oscillations, resulting in fewer neurons responding to refined cortical commands. By adulthood some electrophysiological deficits waned together with hyperlocomotion, but striatal spontaneous activity remained substantially elevated. Moreover, dopamine-depleted animals showing normal locomotor scores exhibited normal corticostriatal synchronization, suggesting that the lesion allows, but is not sufficient, for the emergence of corticostriatal changes and hyperactivity. Although amphetamine normalized corticostriatal tuning in hyperlocomotor mice, it reduced horizontal activity in dopamine-depleted animals regardless of their locomotor phenotype, suggesting that amphetamine modified locomotion through a parallel mechanism, rather than that modified by dopamine depletion. In summary, functional maturation of striatal activity continues after infancy, and early dopamine depletion delays the maturation of core functional capacities of the corticostriatal system.

Dopamine-dependent periadolescent maturation of corticostriatal functional connectivity in mouse

PubMed Central

Galiñanes, Gregorio L.; Taravini, Irene R.E.; Murer, M. Gustavo

2009-01-01

Altered corticostriatal information processing associated with early dopamine systems dysfunction may contribute to attention deficit/hyperactivity disorder (ADHD). Mice with neonatal dopamine-depleting lesions exhibit hyperactivity that wanes after puberty and is reduced by psychostimulants, reminiscent of some aspects of ADHD. To assess whether the maturation of corticostriatal functional connectivity is altered by early dopamine depletion, we examined pre- and post-adolescent urethane-anesthetized mice with or without dopamine-depleting lesions. Specifically, we assessed (1) synchronization between striatal neuron discharges and oscillations in frontal cortex field potentials and (2) striatal neuron responses to frontal cortex stimulation. In adult control mice striatal neurons were less spontaneously active, less responsive to cortical stimulation and more temporally tuned to cortical rhythms than in infants. Striatal neurons from hyperlocomotor mice required more current to respond to cortical input and were less phase-locked to ongoing oscillations, resulting in fewer neurons responding to refined cortical commands. By adulthood some electrophysiological deficits waned together with hyperlocomotion, but striatal spontaneous activity remained substantially elevated. Moreover, dopamine-depleted animals showing normal locomotor scores exhibited normal corticostriatal synchronization, suggesting that the lesion allows, but is not sufficient, for the emergence of corticostriatal changes and hyperactivity. Although amphetamine normalized corticostriatal tuning in hyperlocomotor mice, it reduced horizontal activity in dopamine-depleted animals irrespective of their locomotor phenotype, suggesting that amphetamine modified locomotion through a parallel mechanism, rather than that modified by dopamine depletion. In summary, functional maturation of striatal activity continues after infancy, and early dopamine depletion delays the maturation of core functional capacities of the corticostriatal system. PMID:19244524

Personality maturation around the world: a cross-cultural examination of social-investment theory.

PubMed

Bleidorn, Wiebke; Klimstra, Theo A; Denissen, Jaap J A; Rentfrow, Peter J; Potter, Jeff; Gosling, Samuel D

2013-12-01

During early adulthood, individuals from different cultures across the world tend to become more agreeable, more conscientious, and less neurotic. Two leading theories offer different explanations for these pervasive age trends: Five-factor theory proposes that personality maturation is largely determined by genetic factors, whereas social-investment theory proposes that personality maturation in early adulthood is largely the result of normative life transitions to adult roles. In the research reported here, we conducted the first systematic cross-cultural test of these theories using data from a large Internet-based sample of young adults from 62 nations (N = 884,328). We found strong evidence for universal personality maturation from early to middle adulthood, yet there were significant cultural differences in age effects on personality traits. Consistent with social-investment theory, results showed that cultures with an earlier onset of adult-role responsibilities were marked by earlier personality maturation.

Microstructural correlates of infant functional development: example of the visual pathways.

PubMed

Dubois, Jessica; Dehaene-Lambertz, Ghislaine; Soarès, Catherine; Cointepas, Yann; Le Bihan, Denis; Hertz-Pannier, Lucie

2008-02-20

The development of cognitive functions during childhood relies on several neuroanatomical maturation processes. Among these processes is myelination of the white matter pathways, which speeds up electrical conduction. Quantitative indices of such structural processes can be obtained in vivo with diffusion tensor imaging (DTI), but their physiological significance remains uncertain. Here, we investigated the microstructural correlates of early functional development by combining DTI and visual event-related potentials (VEPs) in 15 one- to 4-month-old healthy infants. Interindividual variations of the apparent conduction speed, computed from the latency of the first positive VEP wave (P1), were significantly correlated with the infants' age and DTI indices measured in the optic radiations. This demonstrates that fractional anisotropy and transverse diffusivity are structural markers of functionally efficient myelination. Moreover, these indices computed along the optic radiations showed an early wave of maturation in the anterior region, with the posterior region catching up later in development, which suggests two asynchronous fronts of myelination in both the geniculocortical and corticogeniculate fibers. Thus, in addition to microstructural information, DTI provides noninvasive exquisite information on the functional development of the brain in human infants.

Surgical management of patients with a history of early Le Fort III advancement after they have attained skeletal maturity.

PubMed

Caterson, E J; Shetye, Pradip R; Grayson, Barry H; McCarthy, Joseph G

2013-10-01

The classic Le Fort III procedure was recommended in syndromic craniosynostotic children to reduce exorbitism, improve airway function, and decrease dysmorphism. This study reports on a cohort of syndromic craniosynostosis patients who have undergone early primary subcranial (classic Tessier) Le Fort III advancement and who have been followed longitudinally through skeletal maturity and beyond. In this study, the Le Fort III advancements all occurred between the ages of 3 to 5 years, with a mean age of 4.6 years. Subsequently, these early Le Fort III patients were followed throughout development with longitudinal dental, medical, radiographic, and photographic evaluations conducted through skeletal maturity and beyond. For study inclusion, the patients had to have preoperative medical photographs and cephalometric studies at 6 months and 1, 5, and 10 years postoperatively after the primary Le Fort III advancement as well as cephalometric documentation 6 months and 1 year after the secondary midface advancement after skeletal maturity. After early or primary Le Fort III advancement, there was no evidence of relapse and only minimal anterior or horizontal postoperative growth of the midface. However, there was also a return of occlusal disharmony from "anticipated" mandibular growth, approaching a maximum at skeletal maturity. The dysmorphic concave facial profile and malocclusion, and airway and ocular considerations, provided the impetus for secondary midface surgery after skeletal maturity was attained. The data demonstrate that early Le Fort III advancement performed before the age of mixed dentition does not obviate the need for a secondary advancement after skeletal maturity is reached. Therapeutic, IV.

Elevated Social Anxiety among Early Maturing Girls

PubMed Central

Blumenthal, Heidemarie; Leen-Feldner, Ellen W.; Babson, Kimberly A.; Gahr, Jessica L.; Trainor, Casey D.; Frala, Jamie L.

2012-01-01

Adolescence is a key period in terms of the development of anxiety psychopathology. An emerging literature suggests that early pubertal maturation is associated with enhanced vulnerability for anxiety symptomatology, although few studies have examined this association with regard to social anxiety. Accordingly, the current study was designed to further elucidate the relation between pubertal timing and social anxiety, with a focus on clarifying the role of gender. Participants were 138 adolescents (ages 12-17 years) recruited from the general community. Level of social anxiety was examined as a function of gender and within-sample pubertal timing. As expected, early-maturing girls evidenced significantly higher social anxiety as compared to on-time girls and early-maturing boys, and no other differences were found as a function of gender or developmental timing. Findings and future directions are discussed in terms of forwarding developmentally-sensitive models of social anxiety etiology and prevention. PMID:21604866

The dimerization of the yeast cytochrome bc1 complex is an early event and is independent of Rip1.

PubMed

Conte, Annalea; Papa, Benedetta; Ferramosca, Alessandra; Zara, Vincenzo

2015-05-01

In Saccharomyces cerevisiae the mature cytochrome bc1 complex exists as an obligate homo-dimer in which each monomer consists of ten distinct protein subunits inserted into or bound to the inner mitochondrial membrane. Among them, the Rieske iron-sulfur protein (Rip1), besides its catalytic role in electron transfer, may be implicated in the bc1 complex dimerization. Indeed, Rip1 has the globular domain containing the catalytic center in one monomer while the transmembrane helix interacts with the adjacent monomer. In addition, the lack of Rip1 leads to the accumulation of an immature bc1 intermediate, only loosely associated with cytochrome c oxidase. In this study we have investigated the biogenesis of the yeast cytochrome bc1 complex using epitope tagged proteins to purify native assembly intermediates. We showed that the dimerization process is an early event during bc1 complex biogenesis and that the presence of Rip1, differently from previous proposals, is not essential for this process. We also investigated the multi-step model of bc1 assembly thereby lending further support to the existence of bona fide subcomplexes during bc1 maturation in the inner mitochondrial membrane. Finally, a new model of cytochrome bc1 complex assembly, in which distinct intermediates sequentially interact during bc1 maturation, has been proposed. Copyright © 2015 Elsevier B.V. All rights reserved.

Composition of natural gas and crude oil produced from 14 wells in the Lower Silurian "Clinton" Sandstone and Medina Group Sandstones, northeastern Ohio and northwestern Pennsylvania: Chapter G.6 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

USGS Publications Warehouse

Burruss, Robert A.; Ryder, Robert T.; Ruppert, Leslie F.; Ryder, Robert T.

2014-01-01

The geochemical processes that control the distribution of hydrocarbons in the regional accumulation of natural gas and crude oil in reservoirs of Early Silurian age in the central Appalachian basin are not well understood. Gas and oil samples from 14 wells along a down-dip transect through the accumulation in northeastern Ohio and northwestern Pennsylvania were analyzed for molecular and stable isotopic compositions to look for evidence of hydrocarbon source, thermal maturation, migration, and alteration parameters. The correlation of carbon and hydrogen stable isotopic composition of methane with thermal maturation indicates that the deepest gases are more thermally mature than independent estimates of thermal maturity of the reservoir horizon based on the conodont alteration index. This correlation indicates that the natural gas charge in the deepest parts of the regional accumulation sampled in this study originated in deeper parts of the Appalachian basin and migrated into place. Other processes, including mixing and late-stage alteration of hydrocarbons, may also impact the observed compositions of natural gases and crude oils.

Analysis of global gene expression profiles to identify differentially expressed genes critical for embryo development in Brassica rapa.

PubMed

Zhang, Yu; Peng, Lifang; Wu, Ya; Shen, Yanyue; Wu, Xiaoming; Wang, Jianbo

2014-11-01

Embryo development represents a crucial developmental period in the life cycle of flowering plants. To gain insights into the genetic programs that control embryo development in Brassica rapa L., RNA sequencing technology was used to perform transcriptome profiling analysis of B. rapa developing embryos. The results generated 42,906,229 sequence reads aligned with 32,941 genes. In total, 27,760, 28,871, 28,384, and 25,653 genes were identified from embryos at globular, heart, early cotyledon, and mature developmental stages, respectively, and analysis between stages revealed a subset of stage-specific genes. We next investigated 9,884 differentially expressed genes with more than fivefold changes in expression and false discovery rate ≤ 0.001 from three adjacent-stage comparisons; 1,514, 3,831, and 6,633 genes were detected between globular and heart stage embryo libraries, heart stage and early cotyledon stage, and early cotyledon and mature stage, respectively. Large numbers of genes related to cellular process, metabolism process, response to stimulus, and biological process were expressed during the early and middle stages of embryo development. Fatty acid biosynthesis, biosynthesis of secondary metabolites, and photosynthesis-related genes were expressed predominantly in embryos at the middle stage. Genes for lipid metabolism and storage proteins were highly expressed in the middle and late stages of embryo development. We also identified 911 transcription factor genes that show differential expression across embryo developmental stages. These results increase our understanding of the complex molecular and cellular events during embryo development in B. rapa and provide a foundation for future studies on other oilseed crops.

[Inflammasome and its role in immunological and inflammatory response at early stage of burns].

PubMed

Zhang, Fang; Li, Jiahui; Xia, Zhaofan

2014-06-01

Inflammasomes are large multi-protein complexes that serve as a platform for caspase-1 activation, and this process induces subsequent maturation and secretion of the proinflammatory cytokines IL-1β and IL-18, as well as pyroptosis. As an important component of the innate immune system, early activation of inflammasomes in a variety of immune cell subsets can mediate inflammatory response and immunological conditions after burn injury. Here, we review the current knowledge of inflammasomes and its role in immunological and inflammatory response at the early stage of burn injury.

Trauma and Early Adolescent Development: Case Examples from a Trauma-Informed Public Health Middle School Program

ERIC Educational Resources Information Center

Frydman, Jason Scott; Mayor, Christine

2017-01-01

Middle-school-age children are faced with a variety of developmental tasks, including the beginning phases of individuation from the family, building peer groups, social and emotional transitions, and cognitive shifts associated with the maturation process. This article summarizes how traumatic events impair and complicate these developmental…

Neural Correlates of Performance Monitoring during the Transition to Young Adulthood

ERIC Educational Resources Information Center

Kneževic, Martina; Veroude, Kim; Jolles, Jelle; Krabbendam, Lydia

2016-01-01

Cognitive challenges during transition to adulthood are generally high and require particular skills, such as self-control, performance evaluation, and behavioral adjustment for success in everyday living. However, age and sex differences in timing and efficiency of brain maturational processes in the early twenties are not well known. We used a…

Functional Dissociation between Perception and Action Is Evident Early in Life

ERIC Educational Resources Information Center

Hadad, Bat-Sheva; Avidan, Galia; Ganel, Tzvi

2012-01-01

The functional distinction between vision for perception and vision for action is well documented in the mature visual system. Ganel and colleagues recently provided direct evidence for this dissociation, showing that while visual processing for perception follows Weber's fundamental law of psychophysics, action violates this law. We tracked the…

C-Terminal HIV-1 Transframe p6* Tetrapeptide Blocks Enhanced Gag Cleavage Incurred by Leucine Zipper Replacement of a Deleted p6* Domain.

PubMed

Yu, Fu-Hsien; Huang, Kuo-Jung; Wang, Chin-Tien

2017-05-15

HIV-1 protease (PR) functions as a homodimer mediating virus maturation following virus budding. Gag-Pol dimerization is believed to trigger embedded PR activation by promoting PR dimer formation. Early PR activation can lead to markedly reduced virus yields due to premature Gag cleavage. The p6* peptide, located between Gag and PR, is believed to ensure virus production by preventing early PR maturation. Studies aimed at finding supporting evidence for this proposal are limited due to a reading frame overlap between p6* and the p6gag budding domain. To determine if p6* affects virus production via the modulation of PR activation, we engineered multiple constructs derived from Dp6*PR (an assembly- and processing-competent construct with Pol fused at the inactivated PR C terminus). The data indicated that a p6* deletion adjacent to active PR significantly impaired virus processing. We also observed that the insertion of a leucine zipper (LZ) dimerization motif in the deleted region eliminated virus production in a PR activity-dependent manner, suggesting that the LZ insertion triggered premature PR activation by facilitating PR dimer formation. As few as four C-terminal p6* residues remaining at the p6*/PR junction were sufficient to restore virus yields, with a Gag processing profile similar to that of the wild type. Our study provides supporting evidence in a virus assembly context that the C-terminal p6* tetrapeptide plays a role in preventing premature PR maturation. IMPORTANCE Supporting evidence for the assumption that p6* retards PR maturation in the context of virus assembly is lacking. We found that replacing p6* with a leucine zipper peptide abolished virus assembly due to the significant enhancement of Gag cleavage. However, as few as four C-terminal p6* residues remaining in the deleted region were sufficient for significant PR release, as well as for counteracting leucine zipper-incurred premature Gag cleavage. Our data provide evidence that (i) p6* ensures virus assembly by preventing early PR activation and (ii) four C-terminal p6* residues are critical for modulating PR activation. Current PR inhibitor development efforts are aimed largely at mature PR, but there is a tendency for HIV-1 variants that are resistant to multiple protease inhibitors to emerge. Our data support the idea of modulating PR activation by targeting PR precursors as an alternative approach to controlling HIV-1/AIDS. Copyright © 2017 American Society for Microbiology.

Cyclic Mechanical Loading Is Essential for Rac1-Mediated Elongation and Remodeling of the Embryonic Mitral Valve.

PubMed

Gould, Russell A; Yalcin, Huseyin C; MacKay, Joanna L; Sauls, Kimberly; Norris, Russell; Kumar, Sanjay; Butcher, Jonathan T

2016-01-11

During valvulogenesis, globular endocardial cushions elongate and remodel into highly organized thin fibrous leaflets. Proper regulation of this dynamic process is essential to maintain unidirectional blood flow as the embryonic heart matures. In this study, we tested how mechanosensitive small GTPases, RhoA and Rac1, coordinate atrioventricular valve (AV) differentiation and morphogenesis. RhoA activity and its regulated GTPase-activating protein FilGAP are elevated during early cushion formation but decreased considerably during valve remodeling. In contrast, Rac1 activity was nearly absent in the early cushions but increased substantially as the valve matured. Using gain- and loss-of-function assays, we determined that the RhoA pathway was essential for the contractile myofibroblastic phenotype present in early cushion formation but was surprisingly insufficient to drive matrix compaction during valve maturation. The Rac1 pathway was necessary to induce matrix compaction in vitro through increased cell adhesion, elongation, and stress fiber alignment. Facilitating this process, we found that acute cyclic stretch was a potent activator of RhoA and subsequently downregulated Rac1 activity via FilGAP. On the other hand, chronic cyclic stretch reduced active RhoA and downstream FilGAP, which enabled Rac1 activation. Finally, we used partial atrial ligation experiments to confirm in vivo that altered cyclic mechanical loading augmented or restricted cushion elongation and thinning, directly through potentiation of active Rac1 and active RhoA, respectively. Together, these results demonstrate that cyclic mechanical signaling coordinates the RhoA to Rac1 signaling transition essential for proper embryonic mitral valve remodeling. Copyright © 2016 Elsevier Ltd. All rights reserved.

Induction of endoplasmic reticulum calcium pump expression during early leukemic B cell differentiation.

PubMed

Aït Ghezali, Lamia; Arbabian, Atousa; Roudot, Hervé; Brouland, Jean-Philippe; Baran-Marszak, Fanny; Salvaris, Evelyn; Boyd, Andrew; Drexler, Hans G; Enyedi, Agnes; Letestu, Remi; Varin-Blank, Nadine; Papp, Bela

2017-06-26

Endoplasmic reticulum (ER) calcium storage and release play important roles in B lymphocyte maturation, survival, antigen-dependent cell activation and immunoglobulin synthesis. Calcium is accumulated in the endoplasmic reticulum (ER) by Sarco/Endoplasmic Reticulum Calcium ATPases (SERCA enzymes). Because lymphocyte function is critically dependent on SERCA activity, it is important to understand qualitative and quantitative changes of SERCA protein expression that occur during B lymphoid differentiation and leukemogenesis. In this work we investigated the modulation of SERCA expression during the pharmacologically induced differentiation of leukemic precursor B lymphoblast cell lines that carry the E2A-PBX1 fusion oncoprotein. Changes of SERCA levels during differentiation were determined and compared to those of established early B lymphoid differentiation markers. SERCA expression of the cells was compared to that of mature B cell lines as well, and the effect of the direct inhibition of SERCA-dependent calcium transport on the differentiation process was investigated. We show that E2A-PBX1 + leukemia cells simultaneously express SERCA2 and SERCA3-type calcium pumps; however, their SERCA3 expression is markedly inferior to that of mature B cells. Activation of protein kinase C enzymes by phorbol ester leads to phenotypic differentiation of the cells, and this is accompanied by the induction of SERCA3 expression. Direct pharmacological inhibition of SERCA-dependent calcium transport during phorbol ester treatment interferes with the differentiation process. These data show that the calcium pump composition of the ER is concurrent with increased SERCA3 expression during the differentiation of precursor B acute lymphoblastic leukemia cells, that a cross-talk exists between SERCA function and the control of differentiation, and that SERCA3 may constitute an interesting new marker for the study of early B cell phenotype.

Injurious effects of curcumin on maturation of mouse oocytes, fertilization and fetal development via apoptosis.

PubMed

Chen, Chia-Chi; Chan, Wen-Hsiung

2012-01-01

Curcumin, a common dietary pigment and spice, is a hydrophobic polyphenol derived from the rhizome of the herb Curcuma longa. Previously, we reported a cytotoxic effect of curcumin on mouse embryonic stem cells and blastocysts and its association with defects in subsequent development. In the present study, we further investigated the effects of curcumin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, curcumin induced a significant reduction in the rate of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with curcumin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments with an in vivo mouse model disclosed that consumption of drinking water containing 40 μM curcumin led to decreased oocyte maturation and in vitro fertilization as well as early embryonic developmental injury. Finally, pretreatment with a caspase-3-specific inhibitor effectively prevented curcumin-triggered injury effects, suggesting that embryo impairment by curcumin occurs mainly via a caspase-dependent apoptotic process.

Low Temperature and Short-Term High-CO2 Treatment in Postharvest Storage of Table Grapes at Two Maturity Stages: Effects on Transcriptome Profiling

PubMed Central

Rosales, Raquel; Romero, Irene; Fernandez-Caballero, Carlos; Escribano, M. Isabel; Merodio, Carmen; Sanchez-Ballesta, M. Teresa

2016-01-01

Table grapes (Vitis vinifera cv. Cardinal) are highly perishable and their quality deteriorates during postharvest storage at low temperature mainly because of sensitivity to fungal decay and senescence of rachis. The application of a 3-day CO2 treatment (20 kPa CO2 + 20 kPa O2 + 60 kPa N2) at 0°C reduced total decay and retained fruit quality in early and late-harvested table grapes during postharvest storage. In order to study the transcriptional responsiveness of table grapes to low temperature and high CO2 levels in the first stage of storage and how the maturity stage affect these changes, we have performed a comparative large-scale transcriptional analysis using the custom-made GrapeGen GeneChip®. In the first stage of storage, low temperature led to a significantly intense change in grape skin transcriptome irrespective of fruit maturity, although there were different changes within each stage. In the case of CO2 treated samples, in comparison to fruit at time zero, only slight differences were observed. Functional enrichment analysis revealed that major modifications in the transcriptome profile of early- and late-harvested grapes stored at 0°C are linked to biotic and abiotic stress-responsive terms. However, in both cases there is a specific reprogramming of the transcriptome during the first stage of storage at 0°C in order to withstand the cold stress. Thus, genes involved in gluconeogenesis, photosynthesis, mRNA translation and lipid transport were up-regulated in the case of early-harvested grapes, and genes related to protein folding stability and intracellular membrane trafficking in late-harvested grapes. The beneficial effect of high CO2 treatment maintaining table grape quality seems to be an active process requiring the induction of several transcription factors and kinases in early-harvested grapes, and the activation of processes associated to the maintenance of energy in late-harvested grapes. PMID:27468290

Morphogenesis and maturation of the embryonic and postnatal intestine.

PubMed

Chin, Alana M; Hill, David R; Aurora, Megan; Spence, Jason R

2017-06-01

The intestine is a vital organ responsible for nutrient absorption, bile and waste excretion, and a major site of host immunity. In order to keep up with daily demands, the intestine has evolved a mechanism to expand the absorptive surface area by undergoing a morphogenetic process to generate finger-like units called villi. These villi house specialized cell types critical for both absorbing nutrients from food, and for protecting the host from commensal and pathogenic microbes present in the adult gut. In this review, we will discuss mechanisms that coordinate intestinal development, growth, and maturation of the small intestine, starting from the formation of the early gut tube, through villus morphogenesis and into early postnatal life when the intestine must adapt to the acquisition of nutrients through food intake, and to interactions with microbes. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Constraining the Thermal History of the Midcontinent Rift System with Clumped Isotopes and Organic Thermal Maturity Indices

NASA Astrophysics Data System (ADS)

Gallagher, T. M.; Sheldon, N. D.; Mauk, J. L.; Gueneli, N.; Brocks, J. J.

2015-12-01

The Mesoproterozoic (~1.1 Ga) North American Midcontinent Rift System (MRS) has been of widespread interest to researchers studying its economic mineral deposits, continental rifting processes, and the evolution of early terrestrial life and environments. For their age, the MRS rocks are well preserved and have not been deeply buried, yet a thorough understanding of the regional thermal history is necessary to constrain the processes that emplaced the mineral deposits and how post-burial alteration may have affected various paleo-records. To understand the thermal history of the MRS better, this study presents carbonate clumped isotope (Δ47) temperatures from deposits on the north and south sides of the rift. Due to the age of these deposits and known post-depositional processes, uncertainties exist about whether the clumped isotope signature has been reset. To test this, three generations of calcite were analyzed from the Nonesuch Fm. from the White Pine mine in Michigan including: sedimentary limestone beds, early diagenetic carbonate nodules, and hydrothermal calcite veins associated with the emplacement of copper mineralization. Clumped isotope temperatures from the White Pine mine range from 84 to 131°C, with a hydrothermal vein producing the hottest temperature. The clumped isotope temperature range for samples throughout the rift expands to 41-134°C. The hottest temperatures are associated with areas of known copper mineralization, whereas the coolest temperatures are found on the northern arm of the rift in Minnesota, far from known basin-bounding faults. Our hottest temperatures are broadly consistent with preexisting maximum thermal temperature estimates based on clay mineralogy, fluid inclusions, and organic geochemistry data. Clumped isotope results will also be compared to new hydrocarbon maturity data from the Nonesuch Fm., which suggest that bitumen maturities consistently fall within the early oil window across Michigan and Wisconsin.

Changes in contractile properties and action potentials of motor units in the rat medial gastrocnemius muscle during maturation.

PubMed

Dobrzynska, Z; Celichowski, J

2016-02-01

The early phase of development of muscles stops following the disappearance of embryonic and neonatal myosin and the elimination of polyneuronal innervation of muscle fibres with the formation of motor units (MUs), but later the muscle mass still considerably increases. It is unknown whether the three types are visible among newly formed MUs soon after the early postnatal period and whether their proportion is similar to that in adult muscle. Moreover, the processes responsible for MU-force regulation by changes in motoneuronal firing rate as well as properties of motor unit action potentials (MUAPs) during maturation are unknown. Three groups of Wistar rats were investigated - 1 month old, 2 months old and the adult, 9 months old. The basic contractile properties and action potentials of MUs in the medial gastrocnemius (MG) muscle were analysed. The three types of MUs were distinguishable in all age groups, but higher proportion of slow MUs was noticed in young rats (29%, 18% and 11% in 1, 2 and 9 months rats, respectively). The fatigue index for fast fatigable MUs in 1 month old rats was about 2 times higher than in 9 months old rats. The twitch time parameters of fast MUs were shortened during the maturation; for these units, the force-frequency curves in young rats were shifted towards lower frequencies, which suggested that fast motoneurons of young animals generate lower firing rates. Higher twitch-to-tetanus ratios noted for the three MU types in young rats suggested the smaller role of rate coding in force regulation processes, and the higher role of MU recruitment in young rats. No significant differences in MUAP parameters between two groups of young and adult animals were observed. Concluding, the maturation process evokes deeper changes in fast MUs than in slow ones.

Transplanted human glial-restricted progenitors can rescue the survival of dysmyelinated mice independent of the production of mature, compact myelin.

PubMed

Lyczek, Agatha; Arnold, Antje; Zhang, Jiangyang; Campanelli, James T; Janowski, Miroslaw; Bulte, Jeff W M; Walczak, Piotr

2017-05-01

The therapeutic effect of glial progenitor transplantation in diseases of dysmyelination is currently attributed to the formation of new myelin. Using magnetic resonance imaging (MRI), we show that the therapeutic outcome in dysmyelinated shiverer mice is dependent on the extent of cell migration but not the presence of mature and compact myelin. Human or mouse glial restricted progenitors (GRPs) were transplanted into rag2 -/ - shiverer mouse neonates and followed for over one year. Mouse GRPs produced mature myelin as detected with multi-parametric MRI, but showed limited migration without extended animal lifespan. In sharp contrast, human GRPs migrated extensively and significantly increased animal survival, but production of mature myelin did not occur until 46weeks post-grafting. We conclude that human GRPs can extend the survival of transplanted shiverer mice prior to production of mature myelin, while mouse GRPs fail to extend animal survival despite the early presence of mature myelin. This paradox suggests that transplanted GRPs provide therapeutic benefits through biological processes other than the formation of mature myelin capable to foster rapid nerve conduction, challenging the current dogma of the primary role of myelination in regaining function of the central nervous system. Copyright © 2017 Elsevier Inc. All rights reserved.

CD101, a Novel Echinocandin, Possesses Potent Antibiofilm Activity against Early and Mature Candida albicans Biofilms.

PubMed

Chandra, Jyotsna; Ghannoum, Mahmoud A

2018-02-01

Currently available echinocandins are generally effective against Candida biofilms, but the recent emergence of resistance has underscored the importance of developing new antifungal agents that are effective against biofilms. CD101 is a long-acting novel echinocandin with distinctive pharmacokinetic properties and improved stability and safety relative to other drugs in the same class. CD101 is currently being evaluated as a once-weekly intravenous (i.v.) infusion for the treatment of candidemia and invasive candidiasis. In this study, we determined (i) the effect of CD101 against early and mature phase biofilms formed by C. albicans in vitro and (ii) the temporal effect of CD101 on the formation of biofilms using time-lapse microscopy (TLM). Early- or mature-phase biofilms were formed on silicone elastomer discs and were exposed to the test compounds for 24 h and quantified by measuring their metabolic activity. Separate batches were observed under a confocal microscope or used to capture TLM images from 0 to 16 h. Measurements of their metabolic activity showed that CD101 (0.25 or 1 μg/ml) significantly prevented adhesion-phase cells from developing into mature biofilms ( P = 0.0062 or 0.0064, respectively) and eradicated preformed mature biofilms ( P = 0.04 or 0.01, respectively) compared to those of untreated controls. Confocal microscopy showed significant reductions in biofilm thicknesses for both early and mature phases ( P < 0.05). TLM showed that CD101 stopped the growth of adhesion- and early-phase biofilms within minutes. CD101-treated hyphae failed to grow into mature biofilms. These results suggest that CD101 may be effective in the prevention and treatment of biofilm-associated nosocomial infections. Copyright © 2018 Chandra and Ghannoum.

Induction of Oligodendrocyte Differentiation and In Vitro Myelination by Inhibition of Rho-Associated Kinase

PubMed Central

Taylor, Christopher; Pereira, Albertina; Seng, Michelle; Tham, Chui-Se; Izrael, Michal; Webb, Michael

2014-01-01

In inflammatory demyelinating diseases such as multiple sclerosis (MS), myelin degradation results in loss of axonal function and eventual axonal degeneration. Differentiation of resident oligodendrocyte precursor cells (OPCs) leading to remyelination of denuded axons occurs regularly in early stages of MS but halts as the pathology transitions into progressive MS. Pharmacological potentiation of endogenous OPC maturation and remyelination is now recognized as a promising therapeutic approach for MS. In this study, we analyzed the effects of modulating the Rho-A/Rho-associated kinase (ROCK) signaling pathway, by the use of selective inhibitors of ROCK, on the transformation of OPCs into mature, myelinating oligodendrocytes. Here we demonstrate, with the use of cellular cultures from rodent and human origin, that ROCK inhibition in OPCs results in a significant generation of branches and cell processes in early differentiation stages, followed by accelerated production of myelin protein as an indication of advanced maturation. Furthermore, inhibition of ROCK enhanced myelin formation in cocultures of human OPCs and neurons and remyelination in rat cerebellar tissue explants previously demyelinated with lysolecithin. Our findings indicate that by direct inhibition of this signaling molecule, the OPC differentiation program is activated resulting in morphological and functional cell maturation, myelin formation, and regeneration. Altogether, we show evidence of modulation of the Rho-A/ROCK signaling pathway as a viable target for the induction of remyelination in demyelinating pathologies. PMID:25289646

Slab replacement maturity guidelines.

DOT National Transportation Integrated Search

2014-04-01

This study investigated the use of maturity method to determine early age strength of concrete in slab : replacement application. Specific objectives were (1) to evaluate effects of various factors on the compressive : maturity-strength relationship ...

Transcriptomic evidence for involvement of reactive oxygen species in Rhizoctonia solani AG1 IA sclerotia maturation

PubMed Central

Wang, Haode; Ma, Zhoujie; Gai, Xiaotong; Sun, Yanqiu; He, Shidao; Liu, Xian; Wang, Yanfeng; Xuan, Yuanhu

2018-01-01

Rhizoctonia solani AG1 IA is a soil-borne fungal phytopathogen that can significantly harm crops resulting in economic loss. This species overwinters in grass roots and diseased plants, and produces sclerotia that infect future crops. R. solani AG1 IA does not produce spores; therefore, understanding the molecular mechanism of sclerotia formation is important for crop disease control. To identify the genes involved in this process for the development of disease control targets, the transcriptomes of this species were determined at three important developmental stages (mycelium, sclerotial initiation, and sclerotial maturation) using an RNA-sequencing approach. A total of 5,016, 6,433, and 5,004 differentially expressed genes (DEGs) were identified in the sclerotial initiation vs. mycelial, sclerotial maturation vs. mycelial, and sclerotial maturation vs. sclerotial initiation stages, respectively. Moreover, gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analyses showed that these DEGs were enriched in diverse categories, including oxidoreductase activity, carbohydrate metabolic process, and oxidation-reduction processes. A total of 12 DEGs were further verified using reverse transcription quantitative PCR. Among the genes examined, NADPH oxidase 1 (NOX1) and superoxide dismutase (SOD) were highly induced in the stages of sclerotial initiation and maturation. In addition, the highest reactive oxygen species (ROS) production levels were detected during sclerotial initiation, and enzyme activities of NOX1, SOD, and catalase (CAT) matched with the gene expression profiles. To further evaluate the role of ROS in sclerotial formation, R. solani AG1 IA was treated with the CAT inhibitor aminotriazole and H2O2, resulting in the early differentiation of sclerotia. Taken together, this study provides useful information toward understanding the molecular basis of R. solani AG1 IA sclerotial formation and maturation, and identified the important role of ROS in these processes. PMID:29938140

Cell wall structures leading to cultivar differences in softening rates develop early during apple (Malus x domestica) fruit growth.

PubMed

Ng, Jovyn K T; Schröder, Roswitha; Sutherland, Paul W; Hallett, Ian C; Hall, Miriam I; Prakash, Roneel; Smith, Bronwen G; Melton, Laurence D; Johnston, Jason W

2013-11-19

There is a paucity of information regarding development of fruit tissue microstructure and changes in the cell walls during fruit growth, and how these developmental processes differ between cultivars with contrasting softening behaviour. In this study we compare two apple cultivars that show different softening rates during fruit development and ripening. We investigate whether these different softening behaviours manifest themselves late during ethylene-induced softening in the ripening phase, or early during fruit expansion and maturation. 'Scifresh' (slow softening) and 'Royal Gala' (rapid softening) apples show differences in cortical microstructure and cell adhesion as early as the cell expansion phase. 'Scifresh' apples showed reduced loss of firmness and greater dry matter accumulation compared with 'Royal Gala' during early fruit development, suggesting differences in resource allocation that influence tissue structural properties. Tricellular junctions in 'Scifresh' were rich in highly-esterified pectin, contributing to stronger cell adhesion and an increased resistance to the development of large airspaces during cell expansion. Consequently, mature fruit of 'Scifresh' showed larger, more angular shaped cells than 'Royal Gala', with less airspaces and denser tissue. Stronger cell adhesion in ripe 'Scifresh' resulted in tissue fracture by cell rupture rather than by cell-to-cell-separation as seen in 'Royal Gala'. CDTA-soluble pectin differed in both cultivars during development, implicating its involvement in cell adhesion. Low pectin methylesterase activity during early stages of fruit development coupled with the lack of immuno-detectable PG was associated with increased cell adhesion in 'Scifresh'. Our results indicate that cell wall structures leading to differences in softening rates of apple fruit develop early during fruit growth and well before the induction of the ripening process.

Cell wall structures leading to cultivar differences in softening rates develop early during apple (Malus x domestica) fruit growth

PubMed Central

2013-01-01

Background There is a paucity of information regarding development of fruit tissue microstructure and changes in the cell walls during fruit growth, and how these developmental processes differ between cultivars with contrasting softening behaviour. In this study we compare two apple cultivars that show different softening rates during fruit development and ripening. We investigate whether these different softening behaviours manifest themselves late during ethylene-induced softening in the ripening phase, or early during fruit expansion and maturation. Results ‘Scifresh’ (slow softening) and ‘Royal Gala’ (rapid softening) apples show differences in cortical microstructure and cell adhesion as early as the cell expansion phase. ‘Scifresh’ apples showed reduced loss of firmness and greater dry matter accumulation compared with ‘Royal Gala’ during early fruit development, suggesting differences in resource allocation that influence tissue structural properties. Tricellular junctions in ‘Scifresh’ were rich in highly-esterified pectin, contributing to stronger cell adhesion and an increased resistance to the development of large airspaces during cell expansion. Consequently, mature fruit of ‘Scifresh’ showed larger, more angular shaped cells than ‘Royal Gala’, with less airspaces and denser tissue. Stronger cell adhesion in ripe ‘Scifresh’ resulted in tissue fracture by cell rupture rather than by cell-to-cell-separation as seen in ‘Royal Gala’. CDTA-soluble pectin differed in both cultivars during development, implicating its involvement in cell adhesion. Low pectin methylesterase activity during early stages of fruit development coupled with the lack of immuno-detectable PG was associated with increased cell adhesion in ‘Scifresh’. Conclusions Our results indicate that cell wall structures leading to differences in softening rates of apple fruit develop early during fruit growth and well before the induction of the ripening process. PMID:24252512

Young Adult Identities and Their Pathways: A Developmental and Life Course Model

PubMed Central

Benson, Janel E.; Elder, Glen H.

2013-01-01

Developmental and life course studies of young adult identities have focused on two dimensions, subjective age and psychosocial maturity. This study examines the developmental synchrony of these two processes. In a longitudinal sample of young adults from Add Health (18 to 22), a person-centered analysis of indicators of these dimensions identified four identity profiles. Two depict early and late patterns of identity; the others represent contrasting types of discordance, “pseudo-adult”, subjective age more advanced than maturation level and “anticipatory”, with subjective age less advanced than maturational level. The profiles vary by gender, socioeconomic status, and race-ethnicity as well as by adolescent (ages12–16) pubertal maturation, psychosocial adjustment, and family context. These results provide support for a more holistic, interdisciplinary understanding of adult identity, and show that young adult identities in the Add Health sample follow differentiated paths into the adult years, with largely unknown consequences for the subsequent life course. PMID:21668096

Forward Genetics Defines Xylt1 as a Key, Conserved Regulator of Early Chondrocyte Maturation and Skeletal Length

PubMed Central

Mis, Emily K.; Liem, Karel F.; Kong, Yong; Schwartz, Nancy B.; Domowicz, Miriam; Weatherbee, Scott D.

2014-01-01

The long bones of the vertebrate body are built by the initial formation of a cartilage template that is later replaced by mineralized bone. The proliferation and maturation of the skeletal precursor cells (chondrocytes) within the cartilage template and their replacement by bone is a highly coordinated process which, if misregulated, can lead to a number of defects including dwarfism and other skeletal deformities. This is exemplified by the fact that abnormal bone development is one of the most common types of human birth defects. Yet, many of the factors that initiate and regulate chondrocyte maturation are not known. We identified a recessive dwarf mouse mutant (pug) from an N-ethyl-N-nitrosourea (ENU) mutagenesis screen. pug mutant skeletal elements are patterned normally during development, but display a ~20% length reduction compared to wild-type embryos. We show that the pug mutation does not lead to changes in chondrocyte proliferation but instead promotes premature maturation and early ossification, which ultimately leads to disproportionate dwarfism. Using sequence capture and high-throughput sequencing, we identified a missense mutation in the Xylosyltransferase 1 (Xylt1) gene in pug mutants. Xylosyltransferases catalyze the initial step in glycosaminoglycan (GAG) chain addition to proteoglycan core proteins, and these modifications are essential for normal proteoglycan function. We show that the pug mutation disrupts Xylt1 activity and subcellular localization, leading to a reduction in GAG chains in pug mutants. The pug mutant serves as a novel model for mammalian dwarfism and identifies a key role for proteoglycan modification in the initiation of chondrocyte maturation. PMID:24161523

Neural Indices of Semantic Processing in Early Childhood Distinguish Eventual Stuttering Persistence and Recovery.

PubMed

Kreidler, Kathryn; Hampton Wray, Amanda; Usler, Evan; Weber, Christine

2017-11-09

Maturation of neural processes for language may lag in some children who stutter (CWS), and event-related potentials (ERPs) distinguish CWS who have recovered from those who have persisted. The current study explores whether ERPs indexing semantic processing may distinguish children who will eventually persist in stuttering (CWS-ePersisted) from those who will recover from stuttering (CWS-eRecovered). Fifty-six 5-year-old children with normal receptive language listened to naturally spoken sentences in a story context. ERP components elicited for semantic processing (N400, late positive component [LPC]) were compared for CWS-ePersisted, CWS-eRecovered, and children who do not stutter (CWNS). The N400 elicited by semantic violations had a more focal scalp distribution (left lateralized and less anterior) in the CWS-eRecovered compared with CWS-ePersisted. Although the LPC elicited in CWS-eRecovered and CWNS did not differ, the LPC elicited in the CWS-ePersisted was smaller in amplitude compared with that in CWNS. ERPs elicited in 5-year-old CWS-eRecovered compared with CWS-ePersisted suggest that future recovery from stuttering may be associated with earlier maturation of semantic processes in the preschool years. Subtle differences in ERP indices offer a window into neural maturation processes for language and may help distinguish the course of stuttering development.

Delineation of early brain development from fetuses to infants with diffusion MRI and beyond.

PubMed

Ouyang, Minhui; Dubois, Jessica; Yu, Qinlin; Mukherjee, Pratik; Huang, Hao

2018-04-12

Dynamic macrostructural and microstructural changes take place from the mid-fetal stage to 2 years after birth. Delineating structural changes of the brain during early development provides new insights into the complicated processes of both typical development and the pathological mechanisms underlying various psychiatric and neurological disorders including autism, attention deficit hyperactivity disorder and schizophrenia. Decades of histological studies have identified strong spatial and functional maturation gradients in human brain gray and white matter. The recent improvements in magnetic resonance imaging (MRI) techniques, especially diffusion MRI (dMRI), relaxometry imaging, and magnetization transfer imaging (MTI) have provided unprecedented opportunities to non-invasively quantify and map the early developmental changes at whole brain and regional levels. Here, we review the recent advances in understanding early brain structural development during the second half of gestation and the first two postnatal years using modern MR techniques. Specifically, we review studies that delineate the emergence and microstructural maturation of white matter tracts, as well as dynamic mapping of inhomogeneous cortical microstructural organization unique to fetuses and infants. These imaging studies converge into maturational curves of MRI measurements that are distinctive across different white matter tracts and cortical regions. Furthermore, contemporary models offering biophysical interpretations of the dMRI-derived measurements are illustrated to infer the underlying microstructural changes. Collectively, this review summarizes findings that contribute to charting spatiotemporally heterogeneous gray and white matter structural development, offering MRI-based biomarkers of typical brain development and setting the stage for understanding aberrant brain development in neurodevelopmental disorders. Copyright © 2018 Elsevier Inc. All rights reserved.

Spacecraft Complexity Subfactors and Implications on Future Cost Growth

NASA Technical Reports Server (NTRS)

Leising, Charles J.; Wessen, Randii; Ellyin, Ray; Rosenberg, Leigh; Leising, Adam

2013-01-01

During the last ten years the Jet Propulsion Laboratory has used a set of cost-risk subfactors to independently estimate the magnitude of development risks that may not be covered in the high level cost models employed during early concept development. Within the last several years the Laboratory has also developed a scale of Concept Maturity Levels with associated criteria to quantitatively assess a concept's maturity. This latter effort has been helpful in determining whether a concept is mature enough for accurate costing but it does not provide any quantitative estimate of cost risk. Unfortunately today's missions are significantly more complex than when the original cost-risk subfactors were first formulated. Risks associated with complex missions are not being adequately evaluated and future cost growth is being underestimated. The risk subfactor process needed to be updated.

Supplementation with CTGF, SDF1, NGF, and HGF promotes ovine in vitro oocyte maturation and early embryo development.

PubMed

Wang, D H; Ren, J; Zhou, C J; Han, Z; Wang, L; Liang, C G

2018-05-17

The strategies for improving the in vitro maturation (IVM) of domestic animal oocytes focus on promoting nuclear and cytoplasmic maturation. The identification of paracrine factors and their supplementation in the culture medium represent effective approaches for oocyte maturation and embryo development. This study investigated the effects of paracrine factor supplementation including connective tissue growth factor (CTGF), nerve growth factor (NGF), hepatocyte growth factor (HGF), and stromal derived factor 1 (SDF1) on ovine oocytes and early parthenogenetic embryos using an in vitro culture system. First, we identified the optimal concentrations of CTGF (30 ng/mL), SDF1 (10 ng/mL), NGF (3 ng/mL), and HGF (100 ng/mL) for promoting oocyte maturation, which combined, induced nuclear maturation in 94.19% of oocytes. This combination also promoted cumulus cell expansion and inhibited oocyte/cumulus apoptosis, while enabling a larger proportion (33.04%) of embryos to develop into blastocysts than in the controls and prevented embryo apoptosis. These novel findings demonstrate that the paracrine factors CTGF, SDF1, NGF, and HGF facilitate ovine oocyte and early parthenogenetic embryo development in vitro. Thus, supplementation with these factors may help optimize the IVM of ovine oocytes and early parthenogenetic embryo development strategies. Copyright © 2018 Elsevier Inc. All rights reserved.

Exploring Play/Playfulness and Learning in the Adult and Higher Education Classroom

ERIC Educational Resources Information Center

Tanis, David J.

2012-01-01

Play and playfulness and their role in learning are researched extensively in early childhood education. However, as the child matures into an adult, play and playfulness are given less attention in the teaching and learning process. In adult education, there is very little research about play/playfulness and its significance for learning. Despite…

Word Learning in 6-Month-Olds: Fast Encoding-Weak Retention

ERIC Educational Resources Information Center

Friedrich, Manuela; Friederici, Angela D.

2011-01-01

There has been general consensus that initial word learning during early infancy is a slow and time-consuming process that requires very frequent exposure, whereas later in development, infants are able to quickly learn a novel word for a novel meaning. From the perspective of memory maturation, this shift in behavioral development might represent…

Correlated Longitudinal Changes across Linguistic, Achievement, and Psychomotor Domains in Early Childhood: Evidence for a Global Dimension of Development

ERIC Educational Resources Information Center

Rhemtulla, Mijke; Tucker-Drob, Elliot M.

2011-01-01

An important question within developmental psychology concerns the extent to which the maturational gains that children make across multiple diverse domains of functioning can be attributed to global (domain-general) developmental processes. The present study investigated this question by examining the extent to which individual differences in…

Injuries and illnesses in a cohort of elite youth alpine ski racers and the influence of biological maturity and relative age: a two-season prospective study

PubMed Central

Müller, Lisa; Hildebrandt, Carolin; Müller, Erich; Oberhoffer, Renate; Raschner, Christian

2017-01-01

Background Studies on injuries and illnesses involving youth ski racers younger than 15 years are lacking in the literature. The aim of this study was prospectively to assess the incidence, prevalence, and severity of traumatic and overuse injuries, as well as illnesses of elite youth ski racers with regard to sex, biological maturity status, and relative age. Subjects and methods A prospective, longitudinal cohort design was used to monitor the anthropometrics, training characteristics, traumatic and overuse injuries, and illnesses of 82 elite youth ski racers (51 males, 31 females, age 9–14 years) over 2 consecutive years. The exact training exposure (skiing and athletic) was recorded. Relative age and estimated biological maturity status were assessed. Results Relatively low injury incidence or prevalence (traumatic, 0.86/1,000 hours of training; overuse, 0.28/1,000 hours) and comparably high illness prevalence (2.4/athlete) were reported. The knee was the most commonly affected body part (traumatic injuries 36.5%, overuse injuries 82%). A high number of bone fractures were revealed (46%), while no stress fractures occurred; 66% of the illnesses were respiratory tract infections. No differences were found between males and females, the differing maturity groups, or relative age quartiles. Early-maturing athletes had comparably low traumatic and overuse-injury rates. Relatively younger athletes had low traumatic injury rates. Conclusion The injury-prevention measures implemented in the training process of youth ski racers seem to contribute to a low incidence of injury. Biological maturity status should be considered in the training process to prevent injuries in late-maturing athletes. PMID:28546774

Elevated Social Anxiety among Early Maturing Girls

ERIC Educational Resources Information Center

Blumenthal, Heidemarie; Leen-Feldner, Ellen W.; Babson, Kimberly A.; Gahr, Jessica L.; Trainor, Casey D.; Frala, Jamie L.

2011-01-01

Adolescence is a key period in terms of the development of anxiety psychopathology. An emerging literature suggests that early pubertal maturation is associated with enhanced vulnerability for anxiety symptomatology, although few studies have examined this association with regard to social anxiety. Accordingly, the current study was designed to…

Genome-wide association mapping of flowering time and maturity dates in early mature soybean germplasm

USDA-ARS?s Scientific Manuscript database

Soybean (Glycine max L. Merr.) is a photoperiod-sensitive and short-day major crop grown worldwide. Days to flowering (DTF) and maturity (DTM) are two traits affecting soybean adaptability and yield. Some genes conditioning soybean flowering and maturity have been recently characterized. However, ...

Maturity-associated variation in physical activity and health-related quality of life in British adolescent girls: moderating effects of peer acceptance.

PubMed

Pindus, Dominika M; Cumming, Sean P; Sherar, Lauren B; Gammon, Catherine; Coelho e Silva, Manuel; Malina, Robert M

2014-01-01

Using a Biocultural Model of Maturity-Associated Variance in physical activity (PA) as a conceptual framework, the main and interactive effects of biological maturity status and perceived peer acceptance on PA and health-related quality of life (HRQoL) in adolescent girls were examined. Three hundred forty-two female British students in years 7 to 9 (13.2±0.83 years) participated in the study. All participants completed the PA Questionnaire for Adolescents and KIDSCREEN-10, a measure of HRQoL. Self-reported perceptions of peer acceptance were measured by items from the National Longitudinal Study of Adolescent Health.Maturity status was estimated as the percentage of predicted adult (mature) height attained at the time of observation. Analysis of covariance suggested an influence of peer acceptance on maturity-associated differences in PA, but not on HRQoL. Girls early and "on time" in maturation with higher perceptions of peer acceptance reported greater involvement in PA than girls early and "on time" in maturation with lower perceptions of peer acceptance. A reverse association was observed for late-maturing girls. Peer acceptance is an important moderator of maturity-associated variation in PA.

Hypothalamic ER–associated degradation regulates POMC maturation, feeding, and age-associated obesity

PubMed Central

Kim, Geun Hyang; Somlo, Diane R.M.; Haataja, Leena; Song, Soobin; Nillni, Eduardo A.

2018-01-01

Pro-opiomelanocortin (POMC) neurons function as key regulators of metabolism and physiology by releasing prohormone-derived neuropeptides with distinct biological activities. However, our understanding of early events in prohormone maturation in the ER remains incomplete. Highlighting the significance of this gap in knowledge, a single POMC cysteine-to-phenylalanine mutation at position 28 (POMC-C28F) is defective for ER processing and causes early onset obesity in a dominant-negative manner in humans through an unclear mechanism. Here, we report a pathologically important role of Sel1L-Hrd1, the protein complex of ER-associated degradation (ERAD), within POMC neurons. Mice with POMC neuron–specific Sel1L deficiency developed age-associated obesity due, at least in part, to the ER retention of POMC that led to hyperphagia. The Sel1L-Hrd1 complex targets a fraction of nascent POMC molecules for ubiquitination and proteasomal degradation, preventing accumulation of misfolded and aggregated POMC, thereby ensuring that another fraction of POMC can undergo normal posttranslational processing and trafficking for secretion. Moreover, we found that the disease-associated POMC-C28F mutant evades ERAD and becomes aggregated due to the presence of a highly reactive unpaired cysteine thiol at position 50. Thus, this study not only identifies ERAD as an important mechanism regulating POMC maturation within the ER, but also provides insights into the pathogenesis of monogenic obesity associated with defective prohormone folding. PMID:29457782

Differential muscular myosin heavy chain expression of the pectoral and pelvic girdles during early growth in the king penguin (Aptenodytes patagonicus) chick.

PubMed

Erbrech, Aude; Robin, Jean-Patrice; Guérin, Nathalie; Groscolas, René; Gilbert, Caroline; Martrette, Jean-Marc

2011-06-01

Continuous growth, associated with a steady parental food supply, is a general pattern in offspring development. So that young chicks can acquire their locomotor independence, this period is usually marked by a fast maturation of muscles, during which different myosin heavy chain (MyHC) isoforms are expressed. However, parental food provisioning may fluctuate seasonally, and offspring therefore face a challenge to ensure the necessary maturation of their tissues when energy is limited. To address this trade-off we investigated muscle maturation in both the pectoral and pelvic girdles of king penguin chicks. This species has an exceptionally long rearing period (1 year), which is prolonged when parental food provisioning is drastically reduced during the sub-Antarctic winter. Approximately 1 month post hatching, chicks acquire a functional pedestrian locomotion, which uses pelvic muscles, whereas swimming, which uses the pectoral muscles, only occurs 1 year later. We therefore tested the hypothesis that the MyHC content of the leg muscles reaches a mature state before those of the pectoral muscles. We found that leg muscle MyHC composition changed with the progressive acquisition of pedestrian locomotion, whereas pectoral muscle fibres reached their mature MyHC profile as early as hatching. Contrary to our predictions, the acquisition of the adult profile in pectoral muscles could be related to an early maturation of the contractile muscular proteins, presumably associated with early thermoregulatory capacities of chicks, necessary for survival in their cold environment. This differential maturation appears to reconcile both the locomotor and environmental constraints of king penguin chicks during growth.

Neuropsychological and Early Maturational Correlates of Intelligence.

ERIC Educational Resources Information Center

Denno, Deborah J.

A study designed to examine biological, sociological, and early maturational correlates of intelligence collected data prospectively, from birth to 15 years of age, on a sample of 987 black children. Multiple indicators of eight independent and three dependent variables were tested in a structural equation model. Altogether, clear sex differences…

Ultrastructural and biochemical evidence for the presence of mature steroidogenic acute regulatory protein (StAR) in the cytoplasm of human luteal cells.

PubMed

Sierralta, Walter D; Kohen, Paulina; Castro, Olga; Muñoz, Alex; Strauss, Jerome F; Devoto, Luigi

2005-10-20

The distribution of the steroidogenic acute regulatory protein (StAR) inside thecal and granulosa-lutein cells of human corpus luteum (CL) was assessed by immunoelectron microscopy. We found greater levels of StAR immunolabeling in steroidogenic cells from early- and mid-than in late luteal phase CL and lower levels in cells from women treated with a GnRH antagonist in the mid-luteal phase. Immunoelectron microscopy revealed significant levels of StAR antigen in the mitochondria and in the cytoplasm of luteal cells. The 30 kDa mature StAR protein was present in both mitochondria and cytosol (post-mitochondrial) fractions from homogenates of CL at different ages, whereas cytochrome c and mitochondrial HSP70 were detected only in the mitochondrial fraction. Therefore, we hypothesized that either appreciable processing of StAR 37 kDa pre-protein occurs outside the mitochondria, or mature StAR protein is selectively released into the cytoplasm after mitochondrial processing. The presence of mature StAR in the cytoplasm is consonant with the notion that StAR acts on the outer mitochondrial membrane to effect sterol import, and that StAR may interact with other cytoplasmic proteins involved in cholesterol metabolism, including hormone sensitive lipase.

Changes in gene expression associated with reproductive maturation in wild female baboons.

PubMed

Babbitt, Courtney C; Tung, Jenny; Wray, Gregory A; Alberts, Susan C

2012-01-01

Changes in gene expression during development play an important role in shaping morphological and behavioral differences, including between humans and nonhuman primates. Although many of the most striking developmental changes occur during early development, reproductive maturation represents another critical window in primate life history. However, this process is difficult to study at the molecular level in natural primate populations. Here, we took advantage of ovarian samples made available through an unusual episode of human-wildlife conflict to identify genes that are important in this process. Specifically, we used RNA sequencing (RNA-Seq) to compare genome-wide gene expression patterns in the ovarian tissue of juvenile and adult female baboons from Amboseli National Park, Kenya. We combined this information with prior evidence of selection occurring on two primate lineages (human and chimpanzee). We found that in cases in which genes were both differentially expressed over the course of ovarian maturation and also linked to lineage-specific selection this selective signature was much more likely to occur in regulatory regions than in coding regions. These results suggest that adaptive change in the development of the primate ovary may be largely driven at the mechanistic level by selection on gene regulation, potentially in relationship to the physiology or timing of female reproductive maturation.

Changes in Gene Expression Associated with Reproductive Maturation in Wild Female Baboons

PubMed Central

Babbitt, Courtney C.; Tung, Jenny; Wray, Gregory A.; Alberts, Susan C.

2012-01-01

Changes in gene expression during development play an important role in shaping morphological and behavioral differences, including between humans and nonhuman primates. Although many of the most striking developmental changes occur during early development, reproductive maturation represents another critical window in primate life history. However, this process is difficult to study at the molecular level in natural primate populations. Here, we took advantage of ovarian samples made available through an unusual episode of human–wildlife conflict to identify genes that are important in this process. Specifically, we used RNA sequencing (RNA-Seq) to compare genome-wide gene expression patterns in the ovarian tissue of juvenile and adult female baboons from Amboseli National Park, Kenya. We combined this information with prior evidence of selection occurring on two primate lineages (human and chimpanzee). We found that in cases in which genes were both differentially expressed over the course of ovarian maturation and also linked to lineage-specific selection this selective signature was much more likely to occur in regulatory regions than in coding regions. These results suggest that adaptive change in the development of the primate ovary may be largely driven at the mechanistic level by selection on gene regulation, potentially in relationship to the physiology or timing of female reproductive maturation. PMID:22155733

Interrelationships among invasive and non-invasive indicators of biological maturation in adolescent male soccer players.

PubMed

Malina, Robert M; Coelho E Silva, Manuel J; Figueiredo, António J; Carling, Christopher; Beunen, Gaston P

2012-01-01

The relationships among indicators of biological maturation were evaluated and concordance between classifications of maturity status in two age groups of youth soccer players examined (11-12 years, n = 87; 13-14 years, n = 93). Data included chronological age (CA), skeletal age (SA, Fels method), stage of pubic hair, predicted age at peak height velocity, and percent of predicted adult height. Players were classified as on time, late or early in maturation using the SA-CA difference, predicted age at peak height velocity, and percent of predicted mature height. Factor analyses indicated two factors in players aged 11-12 years (maturity status: percent of predicted mature height, stage of pubic hair, 59% of variance; maturity timing: SA/CA ratio, predicted age at peak height velocity, 26% of variance), and one factor in players aged 13-14 years (68% of variance). Kappa coefficients were low (0.02-0.23) and indicated poor agreement between maturity classifications. Spearman rank-order correlations between categories were low to moderate (0.16-0.50). Although the indicators were related, concordance of maturity classifications between skeletal age and predicted age at peak height velocity and percent predicted mature height was poor. Talent development programmes call for the classification of youth as early, average, and late maturing for the purpose of designing training and competition programmes. Non-invasive indicators of maturity status have limitations for this purpose.

The maturational theory of brain development and cerebral excitability in the multifactorially inherited manic-depressive psychosis and schizophrenia.

PubMed

Saugstad, L F

1994-12-01

An association has been established between the multifactorially inherited rate of physical maturation and the final step in brain development, when some 40% of synapses are eliminated. This may imply that similarly to endocrine disease entities, we have cerebral disease entities at the extremes of the maturational rate continuum. The restriction of prepubertal pruning to excitatory synapses leaving the number of inhibitory ones fairly constant, implies changes in cerebral excitability as a function of rate of maturation (age at puberty). In early maturation there will be an excess in excitatory drive due to prematurely abridged pruning, which compounds a synchronization tendency inherent in excessive synaptic density. Lowering excitatory level with antiepileptics is hypothesized to be a logical treatment in this type of brain dysfunction. In late maturation, a deficit in excitatory drive due to failure to shut down the pruning process associated with a tendency to the breakdown of circuitry and desynchronization, adds to a similar adversity inherent in reduced synaptic density. Raising the excitatory level with convulsants is hypothesized to be the treatment for this type of CNS dysfunction. The maturational theory of Kraepelin's psychoses holds that they are naturally occurring contrasting chemical signaling disorders in the brain at the extremes of the maturational rate continuum: manic depressive psychosis is a disorder of the early maturer and comprises raised cerebral excitability and a raised density of synapses. This is successfully treated with anti-epileptics like sodium valproate and carbamazepin. Schizophrenia is a disorder in late maturation with reduced cerebral excitability and reduced synaptic density. This is accordingly treated with convulsants such as typical and atypical neuroleptics. However, the conventional effective treatments in both disorders act on inhibition only by either lowering or raising inhibitory level. While the neuroleptics drugs are superior anti-psychotics they nevertheless do not affect the deviation in cerebral excitability which would explain why they do not cure. Disturbed circadian rhythms which precede psychotic episodes in manic depressives accord with a primary dysfunction in the CNS, the suprachiasmatic nucleus of the hypothalamus via its direct input the glutamatergic retinohypothalamic tract. The residual deficits in schizophrenia accord with persistently disconnected circuitry and communication which is a consequence of reduced excitatory level and is manifested in insufficient motivation, a reduced drive associated hypofunction, and neuromuscular dysfunction.

Use of commercial and social sources of alcohol by underage drinkers: the role of pubertal timing.

PubMed

Storvoll, Elisabet E; Pape, Hilde; Rossow, Ingeborg

2008-01-01

We have explored whether alcohol use and procurement of alcohol from commercial and social sources vary with pubertal timing. A sub-sample of 9291 Norwegian minors (13-17 year-olds) was extracted from a nationwide school survey (response rate: 92%). Adolescents who had matured early (early developers, EDs) reported higher consumption and more alcohol-related harm than those who had matured late (late developers, LDs) or at the "normal" time (on time developers, ODs). Purchases from on-premise and off-premise outlets were much more important sources of alcohol for EDs than for ODs and LDs - both in relative and absolute terms. Moreover, EDs were somewhat more likely to obtain alcohol from social sources. Taken together, the findings indicate that adolescents who mature early have access to a larger variety of sources of alcohol than adolescents who mature later - which in turn may explain their increased level of drinking.

Life history of the spottail shiner (Notropis hudsonius) in southeastern Lake Michigan, the Kalamazoo River, and western Lake Erie

USGS Publications Warehouse

Wells, LaRue; House, Robert

1974-01-01

Young shiners started growing earlier in the year than older ones in all three waters. Males and females of the same age resumed growth at about the same time. The growing season began as early as mid-May in the Kalamazoo River and continued as late as September or early October in the other two waters. Small spottail shiners in Lake Michigan and the Kalamazoo River weighed about the same at a given length, but at lengths greater than about 100 mm the lake fish were heavier. In all three waters, spottail shiners matured at about the same length, and males at a somewhat smaller size than females. Smallest mature fish were 65-69 mm long, and the largest immatures were 80-84 mm. In Lake Michigan about half and in Lake Erie about three-quarters of age-I fish were mature, as were all age-II fish in both lakes. In the Kalamazoo River a few fish of age II and all of age III were mature. The spawning season in Lake Michigan in 1964 was from late June or early July to late July, whereas in 1972, which had a colder spring, spawning occurred from mid-July to late August or early September. All shiners in the Kalamazoo River had spawned by the end of June if 1964. Lake Erie spottail shiners spawned during early June to early or mid-July in 1958. Spottail shiners 87-143 mm long from the different waters contained 915 to 8,898 mature eggs.

RAPID COMMUNICATION: Nerve growth factor influences cleavage rate and embryo development in sheep.

PubMed

Crispo, M; Dos Santos-Neto, P C; Vilariño, M; Mulet, A P; de León, A; Barbeito, L; Menchaca, A

2016-10-01

Recent information about Nerve growth factor (NGF), a protein traditionally associated to the nervous system that regulates survival and maturation of developing neurons, suggests that it may exert action also on different levels in the reproductive system. The aim of this study was to evaluate the effect of NGF added during in vitro oocyte maturation, fertilization or in vitro embryo development in sheep. Nerve growth factor was supplemented to the culture medium at 0, 100, or 1,000 ng/mL, during either in vitro maturation (Exp. 1), in vitro fertilization (Exp. 2), or in vitro culture (Exp. 3). In addition, NGF mRNA expression was determined in cumulus cells and oocytes. Nerve growth factor induced early cleavage when added during oocyte maturation or fertilization, improved embryo development when added during fertilization, and had no significant effect when added during embryo culture. In general, the effect was more evident with 100 rather than 1,000 ng/mL (P < 0.05). Expression of endogenous NGF was not detected in oocytes, and increased in cumulus cells when 1,000 ng/mL of NGF was added during fertilization, but not during maturation and embryo culture. In conclusion, the addition of NGF during oocyte maturation and fertilization affects in vitro cleavage and embryo development in sheep. We suggest a possible effect of this growth factor on oocyte maturation and mainly on the fertilization process.

Seed sojourn and fast viability loss constrain seedling production of a prominent riparian protection plant Salix variegata Franch

PubMed Central

Ayi, Qiaoli; Zeng, Bo; Liu, Jianhui; Shi, Shaohua; Niu, Hangang; Lin, Feng; Zhang, Yeyi

2016-01-01

Salix variegata Franch, a prominent plant applied in riparian shelter vegetation in Three Gorges reservoir region of China, produces many seeds every year but generates only a few or no seedlings. Whether the low seedling production of S. variegata is caused by seed sterility or by rapid loss of seed viability remains unknown. We investigated the sojourn time of mature seeds in capsules produced in early, mid, and late reproductive season and the germinability of mature seeds fresh or stored after different period of time. The sojourn time of seeds in capsules was 2.89, 3.95, and 4.72 days in early, mid, and late reproductive season, respectively. The maximal germination percentage of non-stored fresh seeds produced in early, mid, and late reproductive season was 93.33%, 78.67%, and 40%, respectively, which indicates mature seeds were not sterile. The longest viability-retaining time of seeds produced in early, mid, and late reproductive season was only 8, 16, 16 days, respectively, indicating that mature seeds of S. variegata lost viability very rapidly. Mature seeds possessed good viability, but their rapid viability loss caused the low seedling production and hampered the population growth of S. variegata in the riparian area of Three Gorges reservoir region. PMID:27881868

Seed sojourn and fast viability loss constrain seedling production of a prominent riparian protection plant Salix variegata Franch.

PubMed

Ayi, Qiaoli; Zeng, Bo; Liu, Jianhui; Shi, Shaohua; Niu, Hangang; Lin, Feng; Zhang, Yeyi

2016-11-24

Salix variegata Franch, a prominent plant applied in riparian shelter vegetation in Three Gorges reservoir region of China, produces many seeds every year but generates only a few or no seedlings. Whether the low seedling production of S. variegata is caused by seed sterility or by rapid loss of seed viability remains unknown. We investigated the sojourn time of mature seeds in capsules produced in early, mid, and late reproductive season and the germinability of mature seeds fresh or stored after different period of time. The sojourn time of seeds in capsules was 2.89, 3.95, and 4.72 days in early, mid, and late reproductive season, respectively. The maximal germination percentage of non-stored fresh seeds produced in early, mid, and late reproductive season was 93.33%, 78.67%, and 40%, respectively, which indicates mature seeds were not sterile. The longest viability-retaining time of seeds produced in early, mid, and late reproductive season was only 8, 16, 16 days, respectively, indicating that mature seeds of S. variegata lost viability very rapidly. Mature seeds possessed good viability, but their rapid viability loss caused the low seedling production and hampered the population growth of S. variegata in the riparian area of Three Gorges reservoir region.

Protracted development of executive and mnemonic brain systems underlying working memory in adolescence: A longitudinal fMRI study.

PubMed

Simmonds, Daniel J; Hallquist, Michael N; Luna, Beatriz

2017-08-15

Working memory (WM), the ability to hold information on-line to guide planned behavior, improves through adolescence in parallel with continued maturation of critical brain systems supporting cognitive control. Initial developmental neuroimaging studies with one or two timepoints have provided important though varied results limiting our understanding of which and how neural systems change during this transition into mature WM. In this study, we leverage functional magnetic resonance imaging (fMRI) longitudinal data spanning up to 9 years in 129 normally developing individuals to identify which systems demonstrate growth changes that accompany improvements in WM performance. We used a memory guided saccade task that allowed us to probe encoding, pure maintenance, and retrieval neural processes of WM. Consistent with prior research, we found that WM performance continued to improve into the early 20's. fMRI region of interest (ROI) analyses revealed developmental (1) increases in sensorimotor-related (encoding/retrieval) activity in visual cortex from childhood through early adulthood that were associated with WM accuracy and (2) decreases in sustained (maintenance) activity in executive regions from childhood through mid-adolescence that were associated with response latency in childhood and early adolescence. Together these results provide compelling evidence that underlying the maturation of WM is a transition from reliance on executive systems to specialized regions related to the domain of mnemonic requirements of the task leading to optimal performance. Copyright © 2017. Published by Elsevier Inc.

Earliness per se QTLs and their interaction with the photoperiod insensitive allele Ppd-D1a in the Cutler × AC Barrie spring wheat population.

PubMed

Kamran, A; Iqbal, M; Navabi, A; Randhawa, H; Pozniak, C; Spaner, D

2013-08-01

Earliness per se regulates flowering time independent of environmental signals and helps to fine tune the time of flowering and maturity. In this study, we aimed to map earliness per se quantitative trait loci (QTLs) affecting days to flowering and maturity in a population developed by crossing two spring wheat cultivars, Cutler and AC Barrie. The population of 177 recombinant inbred lines (RILs) was genotyped for a total of 488 SSR and DArT polymorphic markers on all 21 chromosomes. Three QTLs of earliness per se affecting days to flowering and maturity were mapped on chromosomes 1B (QEps.dms-1B1 and QEps.dms-1B2) and 5B (QEps.dms-5B1), in individual environments and when all the environments were combined. A QTL affecting flowering time (QFlt.dms-4A1) was identified on chromosome 4A. Two grain yield QTLs were mapped on chromosome 5B, while one QTL was mapped on chromosome 1D. The population segregated for the photoperiod insensitive gene, Ppd-D1a, and it induced earlier flowering by 0.69 days and maturity by 1.28 days. The photoperiod insensitive allele Ppd-D1a interacted in an additive fashion with QTLs for flowering and maturity times. The earliness per se QTL QFlt.dms-5B.1 inducing earlier flowering could help to elongate grain filling duration for higher grain yield. Hence, chromosome 5B possesses promising genomic regions that may be introgressed for higher grain yield with earlier maturity through marker-assisted selection in bread wheat.

Early Maturity of Face Recognition: No Childhood Development of Holistic Processing, Novel Face Encoding, or Face-Space

ERIC Educational Resources Information Center

Crookes, Kate; McKone, Elinor

2009-01-01

Historically, it was believed the perceptual mechanisms involved in individuating faces developed only very slowly over the course of childhood, and that adult levels of expertise were not reached until well into adolescence. Over the last 10 years, there has been some erosion of this view by demonstrations that all adult-like behavioural…

Injurious Effects of Emodin on Maturation of Mouse Oocytes, Fertilization and Fetal Development via Apoptosis

PubMed Central

Chang, Mei-Hui; Chang, Shao-Chung; Chan, Wen-Hsiung

2012-01-01

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), a major constituent of rhubarb, has a wide range of therapeutic applications. Previous studies have established that emodin induces apoptosis in the inner cell mass and trophectoderm of mouse blastocysts and leads to decreased embryonic development and viability, indicating a role as an injury risk factor for normal embryonic development. However, the mechanisms underlying its hazardous effects have yet to be characterized. In the current study, we further investigated the effects of emodin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, emodin induced a significant reduction in the rates of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with emodin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments using an in vivo mouse model disclosed that consumption of drinking water containing 20–40 μM emodin led to decreased oocyte maturation and in vitro fertilization, as well as early embryonic developmental injury. Notably, pretreatment with a caspase-3-specific inhibitor effectively prevented emodin-triggered injury effects, suggesting that impairment of embryo development occurs via a caspase-dependent apoptotic process. PMID:23203041

Injurious effects of emodin on maturation of mouse oocytes, fertilization and fetal development via apoptosis.

PubMed

Chang, Mei-Hui; Chang, Shao-Chung; Chan, Wen-Hsiung

2012-10-29

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), a major constituent of rhubarb, has a wide range of therapeutic applications. Previous studies have established that emodin induces apoptosis in the inner cell mass and trophectoderm of mouse blastocysts and leads to decreased embryonic development and viability, indicating a role as an injury risk factor for normal embryonic development. However, the mechanisms underlying its hazardous effects have yet to be characterized. In the current study, we further investigated the effects of emodin on oocyte maturation and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, emodin induced a significant reduction in the rates of oocyte maturation, fertilization, and in vitro embryonic development. Treatment of oocytes with emodin during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased fetal weight. Experiments using an in vivo mouse model disclosed that consumption of drinking water containing 20-40 μM emodin led to decreased oocyte maturation and in vitro fertilization, as well as early embryonic developmental injury. Notably, pretreatment with a caspase-3-specific inhibitor effectively prevented emodin-triggered injury effects, suggesting that impairment of embryo development occurs via a caspase-dependent apoptotic process.

First study of vitellogenesis of the broad fish tapeworm Diphyllobothrium latum (Cestoda, Diphyllobothriidea), a human parasite with extreme fecundity.

PubMed

Yoneva, Aneta; Kuchta, Roman; Scholz, Tomáš

2014-12-01

In the present study, the process of vitellogenesis of one of the most prolific organisms, the broad tapeworm, Diphyllobothrium latum, the causative agent of human diphyllobothriosis, was studied for the first time using transmission electron microscopy. Cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for detection of glycogen was applied. Starting from the periphery toward the center of the vitelline follicle four stages of vitellocytes are differentiated: immature vitellocytes, early maturing vitellocytes, advanced maturing and mature vitellocytes. Differentiation into mature vitellocytes involves the formation of shell globule clusters containing shell globules, large amount of saturated lipid droplets and glycogen. A peculiar ultrastructural feature of D. latum vitellogenesis is the presence of lamellar bodies in the cytoplasm of mature vitellocytes. This feature is similar to that present in the closely related caryophyllideans and spathebothriideans. Despite the great similarity observed in the embryonic development of diphylobothriideans, caryophyllideans and spathebothriideans, and the fact that their vitellocytes share a feature not reported from other cestode groups, there are substantial differences in the morphology of vitelline clusters, types, amount and localization of their nutritive reserves. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The Value of Comparative Approaches to our Understanding of Puberty as Illustrated by Investigations in Birds and Reptiles

PubMed Central

Ball, Gregory F.; Wade, Juli

2013-01-01

Studies of birds and reptiles have provided many basic insights into the neuroendocrine control of reproductive processes. This research has elucidated mechanisms regulating both early development, including sexual differentiation, and adult neuroendocrine function and behavior. However, phenomena associated with the transition into sexual maturation (puberty) have not been a focus of investigators working on species in these taxonomic classes. Research is complicated in birds and reptiles by a variety of factors, including what can be extended times to maturation, the need to reach particular body size regardless of age, and environmental conditions that can support or inhibit endocrine responses. However, careful selection of model systems, particularly those with available genetic tools, will lead to important comparative studies that can elucidate both generalizability and diversity of mechanisms regulating the onset of reproductive maturity. PMID:23998665

Mammalian brain development and our grandmothering life history.

PubMed

Hawkes, Kristen; Finlay, Barbara L

2018-05-02

Among mammals, including humans, adult brain size and the relative size of brain components depend precisely on the duration of a highly regular process of neural development. Much wider variation is seen in rates of body growth and the state of neural maturation at life history events like birth and weaning. Large brains result from slow maturation, which in humans is accompanied by weaning early with respect to both neural maturation and longevity. The grandmother hypothesis proposes this distinctive combination of life history features evolved as ancestral populations began to depend on foods that just weaned juveniles couldn't handle. Here we trace possible reciprocal connections between brain development and life history, highlighting the resulting extended neural plasticity in a wider cognitive ecology of allomaternal care that distinguishes human ontogeny with consequences for other peculiarities of our lineage. Copyright © 2018 Elsevier Inc. All rights reserved.

Cholinergic systems are essential for late-stage maturation and refinement of motor cortical circuits

PubMed Central

Ramanathan, Dhakshin S.; Conner, James M.; Anilkumar, Arjun A.

2014-01-01

Previous studies reported that early postnatal cholinergic lesions severely perturb early cortical development, impairing neuronal cortical migration and the formation of cortical dendrites and synapses. These severe effects of early postnatal cholinergic lesions preclude our ability to understand the contribution of cholinergic systems to the later-stage maturation of topographic cortical representations. To study cholinergic mechanisms contributing to the later maturation of motor cortical circuits, we first characterized the temporal course of cortical motor map development and maturation in rats. In this study, we focused our attention on the maturation of cortical motor representations after postnatal day 25 (PND 25), a time after neuronal migration has been accomplished and cortical volume has reached adult size. We found significant maturation of cortical motor representations after this time, including both an expansion of forelimb representations in motor cortex and a shift from proximal to distal forelimb representations to an extent unexplainable by simple volume enlargement of the neocortex. Specific cholinergic lesions placed at PND 24 impaired enlargement of distal forelimb representations in particular and markedly reduced the ability to learn skilled motor tasks as adults. These results identify a novel and essential role for cholinergic systems in the late refinement and maturation of cortical circuits. Dysfunctions in this system may constitute a mechanism of late-onset neurodevelopmental disorders such as Rett syndrome and schizophrenia. PMID:25505106

The science behind the proposed maturity standard change

USDA-ARS?s Scientific Manuscript database

The current maturity standard for navel oranges in California has been in place for nearly 100 years yet does not always do a good job of ensuring that consumers obtain good-tasting fruit during the early season. Early work that was performed which supported adoption of the standard may have been ad...

Registration of oilseed sunflower restorer germplasms RHA 476 and RHA 477, adapted for short season environments

USDA-ARS?s Scientific Manuscript database

Northward expansion and double crop use of sunflower (Helianthus annuus L.) is limited by the lack of commercial hybrids with early maturity. We seek to provide the sunflower industry with new, early maturing restorer inbred germplasms with high yield potential and favorable agronomic and seed oil t...

[Age of puberty and western young women sexuality].

PubMed

Tresch, C; Ohl, J

2015-02-01

The onset of menarche and age of first sexual experience have both lowered over the past century. Does the age of puberty influence the sexuality of the girl/young occidental woman? If so, to what degree? Besides, is the acquisition of reproductive function, regardless of age, a sign of sufficient maturity to engage in sexual activity? Studies show that early puberty, early sex, unprotected sexual intercourse in adolescence and number of sexual partners in early adulthood are closely related. These early sexual experiences could be stimulated by early drug use as well as by depressive disorders. The age of puberty has a real influence on sexuality but this link will be modulated by a number of social behavioral factors and it is not sustainable. The age of puberty is not a good indicator of maturity for teenage sexuality; early maturation and early sexual activity are usually associated with risky behaviors. However, other studies on the subject are required, including a consideration of the issues associated with delayed puberty, a subject virtually absent from the literature. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Maturity- and sex-related changes in tibial bone geometry, strength and bone-muscle strength indices during growth: a 20-month pQCT study.

PubMed

Macdonald, Heather M; Kontulainen, Saija A; Mackelvie-O'Brien, Kerry J; Petit, Moira A; Janssen, Patricia; Khan, Karim M; McKay, Heather A

2005-06-01

During growth, bone strength is conferred through subtle adaptations in bone mass and geometry in response to muscle forces. Few studies have examined the changes in bone geometry, strength and the bone-muscle strength relationship across maturity in boys and girls. Our aims were to describe (i) 20-month changes in bone geometry and strength at the tibial midshaft across three maturity groups of boys and girls, (ii) differences in these adaptations between sexes at the same approximate level of maturity and (iii) the bone-muscle strength relationship across maturity groups of boys and girls and between sexes. We used peripheral quantitative computed tomography (pQCT, Stratec XCT-2000) to measure change in total bone cross-sectional area (ToA, mm(2)), cortical area (CoA, mm(2)), average cortical thickness (C.Th., mm), section modulus (mm(3)) and muscle cross-sectional area (mm(2)) at the tibial midshaft (50% site) in 128 EARLY-, PERI- and POST-pubertal girls (n = 69, 11.9 +/- 0.6 years) and boys (n = 59, 12.0 +/- 0.6 years) across 20 months. We also calculated two bone-muscle strength indices (BMSI) for compression (CoA/MCSA) and bending [strength index/MCSA; where strength index = Z / (tibial length / 2)]. EARLY boys and girls had smaller ToA at baseline than same sex PERI or POST participants. There were no sex differences in ToA or CoA at baseline; however, boys increased both parameters significantly more than girls in every maturity group (8.5-11.1%, P < 0.01). These changes in bone geometry conferred greater gains in bone strength for boys compared with girls in each maturity group (13.8-15.6%, P < 0.01). Baseline BMSIs did not differ between sexes for EARLY and PERI groups, whereas BMSIs were significantly higher for POST boys compared with POST girls (P < 0.05). BMSIs decreased for EARLY and PERI girls (-7.4-(-1.1%)) whereas the ratios remained stable for EARLY and PERI boys (-0.6-2.5%). This sex difference in BMSI change was due to a relatively greater increase in CoA among EARLY and PERI boys compared with same-maturity girls. BMSIs remained stable in POST girls and decreased in POST boys due to relatively greater gains in MCSA. This study provides novel longitudinal descriptions of the maturity- and sex-specific changes in bone geometry, strength and bone-muscle strength indices.

Study of cartilage and bone layers of the bearing surface of the equine metacarpophalangeal joint relative to different timescales of maturation.

PubMed

van der Harst, M R; van de Lest, C H A; Degroot, J; Kiers, G H; Brama, P A J; van Weeren, P R

2005-05-01

A detailed and comprehensive insight into the normal maturation process of the different tissues that make up functional units of the locomotor system such as joints is necessary to understand the influence of early training on musculoskeletal tissues. To study simultaneously the maturation process in the entire composite structure that makes up the bearing surface of a joint (cartilage, subchondral and trabecular bone) in terms of biochemical changes in the tissues of juvenile horses at 2 differently loaded sites of the metacarpophalangeal joint, compared to a group of mature horses. In all the structures described above developmental changes may follow a different timescale. Age-related changes in biochemical characteristics of the collagen part of the extracellular matrix (hydroxylysine, hydroxyproline, hydroxypyridinum crosslinks) of articular cartilage and of the underlying subchondral and trabecular bone were determined in a group of juvenile horses (n = 13) (Group 1, age 6 months-4 years) and compared to a group of mature horses (n = 30) (Group 2, >4 years). In both bony layers, bone mineral density, ash content and levels of individual minerals were determined. In cartilage, subchondral bone and trabecular bone, virtually all collagen parameters in juvenile horses were already at a similar (stable) level as in mature horses. In both bony layers, bone mineral density, ash- and calcium content were also stable in the mature horses, but continued to increase in the juvenile group. For magnesium there was a decrease in the juvenile animals, followed by a steady state in the mature horses. In horses age 6 months-4 years, the collagen network of all 3 layers within the joint has already attained a mature biochemical composition, but the mineral composition of both subchondral and trabecular bone continues to develop until approximately age 4 years. The disparity in maturation of the various extracellular matrix components of a joint can be assumed to have consequences for the capacity to sustain load and should hence be taken into account when training or racing young animals.

Forward genetics defines Xylt1 as a key, conserved regulator of early chondrocyte maturation and skeletal length.

PubMed

Mis, Emily K; Liem, Karel F; Kong, Yong; Schwartz, Nancy B; Domowicz, Miriam; Weatherbee, Scott D

2014-01-01

The long bones of the vertebrate body are built by the initial formation of a cartilage template that is later replaced by mineralized bone. The proliferation and maturation of the skeletal precursor cells (chondrocytes) within the cartilage template and their replacement by bone is a highly coordinated process which, if misregulated, can lead to a number of defects including dwarfism and other skeletal deformities. This is exemplified by the fact that abnormal bone development is one of the most common types of human birth defects. Yet, many of the factors that initiate and regulate chondrocyte maturation are not known. We identified a recessive dwarf mouse mutant (pug) from an N-ethyl-N-nitrosourea (ENU) mutagenesis screen. pug mutant skeletal elements are patterned normally during development, but display a ~20% length reduction compared to wild-type embryos. We show that the pug mutation does not lead to changes in chondrocyte proliferation but instead promotes premature maturation and early ossification, which ultimately leads to disproportionate dwarfism. Using sequence capture and high-throughput sequencing, we identified a missense mutation in the Xylosyltransferase 1 (Xylt1) gene in pug mutants. Xylosyltransferases catalyze the initial step in glycosaminoglycan (GAG) chain addition to proteoglycan core proteins, and these modifications are essential for normal proteoglycan function. We show that the pug mutation disrupts Xylt1 activity and subcellular localization, leading to a reduction in GAG chains in pug mutants. The pug mutant serves as a novel model for mammalian dwarfism and identifies a key role for proteoglycan modification in the initiation of chondrocyte maturation. © 2013 Published by Elsevier Inc.

The early development of brain white matter: a review of imaging studies in fetuses, newborns and infants.

PubMed

Dubois, J; Dehaene-Lambertz, G; Kulikova, S; Poupon, C; Hüppi, P S; Hertz-Pannier, L

2014-09-12

Studying how the healthy human brain develops is important to understand early pathological mechanisms and to assess the influence of fetal or perinatal events on later life. Brain development relies on complex and intermingled mechanisms especially during gestation and first post-natal months, with intense interactions between genetic, epigenetic and environmental factors. Although the baby's brain is organized early on, it is not a miniature adult brain: regional brain changes are asynchronous and protracted, i.e. sensory-motor regions develop early and quickly, whereas associative regions develop later and slowly over decades. Concurrently, the infant/child gradually achieves new performances, but how brain maturation relates to changes in behavior is poorly understood, requiring non-invasive in vivo imaging studies such as magnetic resonance imaging (MRI). Two main processes of early white matter development are reviewed: (1) establishment of connections between brain regions within functional networks, leading to adult-like organization during the last trimester of gestation, (2) maturation (myelination) of these connections during infancy to provide efficient transfers of information. Current knowledge from post-mortem descriptions and in vivo MRI studies is summed up, focusing on T1- and T2-weighted imaging, diffusion tensor imaging, and quantitative mapping of T1/T2 relaxation times, myelin water fraction and magnetization transfer ratio. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Embryo sac formation and early embryo development in Agave tequilana (Asparagaceae).

PubMed

González-Gutiérrez, Alejandra G; Gutiérrez-Mora, Antonia; Rodríguez-Garay, Benjamín

2014-01-01

Agave tequilana is an angiosperm species that belongs to the family Asparagaceae (formerly Agavaceae). Even though there is information regarding to some aspects related to the megagametogenesis of A. tequilana, this is the first report describing the complete process of megasporogenesis, megagametogenesis, the early embryo and endosperm development process in detail. The objective of this work was to study and characterize all the above processes and the distinctive morphological changes of the micropylar and chalazal extremes after fertilization in this species. The agave plant material for the present study was collected from commercial plantations in the state of Jalisco, Mexico. Ovules and immature seeds, previously fixed in FAA and kept in ethanol 70%, were stained based on a tissue clarification technique by using a Mayer's-Hematoxylin solution. The tissue clarification technique was successfully used for the characterization of the megasporogenesis, megagametogenesis, mature embryo sac formation, the early embryo and endosperm development processes by studying intact cells. The embryo sac of A. tequilana was confirmed to be of the monosporic Polygonum-type and an helobial endosperm formation. Also, the time-lapse of the developmental processes studied was recorded.

Event-related potential and eye tracking evidence of the developmental dynamics of face processing.

PubMed

Meaux, Emilie; Hernandez, Nadia; Carteau-Martin, Isabelle; Martineau, Joëlle; Barthélémy, Catherine; Bonnet-Brilhault, Frédérique; Batty, Magali

2014-04-01

Although the wide neural network and specific processes related to faces have been revealed, the process by which face-processing ability develops remains unclear. An interest in faces appears early in infancy, and developmental findings to date have suggested a long maturation process of the mechanisms involved in face processing. These developmental changes may be supported by the acquisition of more efficient strategies to process faces (theory of expertise) and by the maturation of the face neural network identified in adults. This study aimed to clarify the link between event-related potential (ERP) development in response to faces and the behavioral changes in the way faces are scanned throughout childhood. Twenty-six young children (4-10 years of age) were included in two experimental paradigms, the first exploring ERPs during face processing, the second investigating the visual exploration of faces using an eye-tracking system. The results confirmed significant age-related changes in visual ERPs (P1, N170 and P2). Moreover, an increased interest in the eye region and an attentional shift from the mouth to the eyes were also revealed. The proportion of early fixations on the eye region was correlated with N170 and P2 characteristics, highlighting a link between the development of ERPs and gaze behavior. We suggest that these overall developmental dynamics may be sustained by a gradual, experience-dependent specialization in face processing (i.e. acquisition of face expertise), which produces a more automatic and efficient network associated with effortless identification of faces, and allows the emergence of human-specific social and communication skills. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Maturity and medical students' ease of transition into the clinical environment.

PubMed

Shacklady, Jaine; Holmes, Eileen; Mason, Graham; Davies, Ioan; Dornan, Tim

2009-07-01

Medical education has been characterized in terms of points of transition, which are accentuated by lack of relevant prior experience and can lead to extreme positive and negative emotions. Quantify the effect of maturity on medical students' transitions into the clinical environment and identify how experiences of transition might be improved. Eleven weeks after entering the clinical environment, 29 mature students (age over 21 at entry, median age 22) in a horizontally-integrated, predominantly undergraduate entry, problem-based curriculum offering little early clinical exposure and 58 matched non-mature students (median age 18 years) rated their experiences of transition and wrote free text comments about them. 62% of mature students compared with 24% of controls described 'good transitions' (odds ratio [OR] for a good transition 6.1; p = 0.002) and mature students were more likely than controls to describe how they drew on their previous years in medical school (OR 2.7, p = 0.04) and their wider life experiences in making the transition (OR 3.9, p = 0.01). They were less likely to feel confused or daunted. Whether mature or not, prior workplace experience, having learned the theory of medicine by PBL, and being confident in their knowledge and skills helped students' transitions. Both mature and non-mature students valued the support of teachers and peers and would have valued clinical experience earlier. The fact that just a few extra years of life experience made such a large difference to students' experiences of transition illustrates how important social factors are in the personal development of medical students. In respondents' views, early clinical experience and early skills training could ease students' passage into the clerkship phase of their education.

Understanding the Link Between Pubertal Timing in Girls and the Development of Depressive Symptoms: The Role of Sexual Harassment.

PubMed

Skoog, Therése; Bayram Özdemir, Sevgi; Stattin, Håkan

2016-02-01

The link between sexual maturation, or pubertal timing, in girls and adolescent depressive symptoms is well-documented, but the underlying processes remain unclear. We examined whether sexual harassment, which has previously been linked to both pubertal timing and depressive symptoms, mediates this link, using a two-wave longitudinal study including 454 girls in 7th (M age  = 13.42, SD = .53) and 8th grade (M age  = 14.42, SD = .55). Pubertal timing was linked to depressive symptoms in both age groups, and predicted an increase in depressive symptoms among the 7th graders. Sexual harassment significantly mediated the link between pubertal timing and depressive symptoms among the 7th, but not the 8th grade girls. Together, our findings suggest that one way to prevent depressive symptoms among early-maturing girls could be to address sexual harassment in preventive intervention in early adolescence.

LANGUAGE DEVELOPMENT. The developmental dynamics of marmoset monkey vocal production.

PubMed

Takahashi, D Y; Fenley, A R; Teramoto, Y; Narayanan, D Z; Borjon, J I; Holmes, P; Ghazanfar, A A

2015-08-14

Human vocal development occurs through two parallel interactive processes that transform infant cries into more mature vocalizations, such as cooing sounds and babbling. First, natural categories of sounds change as the vocal apparatus matures. Second, parental vocal feedback sensitizes infants to certain features of those sounds, and the sounds are modified accordingly. Paradoxically, our closest living ancestors, nonhuman primates, are thought to undergo few or no production-related acoustic changes during development, and any such changes are thought to be impervious to social feedback. Using early and dense sampling, quantitative tracking of acoustic changes, and biomechanical modeling, we showed that vocalizations in infant marmoset monkeys undergo dramatic changes that cannot be solely attributed to simple consequences of growth. Using parental interaction experiments, we found that contingent parental feedback influences the rate of vocal development. These findings overturn decades-old ideas about primate vocalizations and show that marmoset monkeys are a compelling model system for early vocal development in humans. Copyright © 2015, American Association for the Advancement of Science.

Sex-specific cognitive abnormalities in early-onset psychosis.

PubMed

Ruiz-Veguilla, Miguel; Moreno-Granados, Josefa; Salcedo-Marin, Maria D; Barrigon, Maria L; Blanco-Morales, Maria J; Igunza, Evelio; Cañabate, Anselmo; Garcia, Maria D; Guijarro, Teresa; Diaz-Atienza, Francisco; Ferrin, Maite

2017-01-01

Brain maturation differs depending on the area of the brain and sex. Girls show an earlier peak in maturation of the prefrontal cortex. Although differences between adult females and males with schizophrenia have been widely studied, there has been less research in girls and boys with psychosis. The purpose of this study was to examine differences in verbal and visual memory, verbal working memory, auditory attention, processing speed, and cognitive flexibility between boys and girls. We compared a group of 80 boys and girls with first-episode psychosis to a group of controls. We found interactions between group and sex in verbal working memory (p = 0.04) and auditory attention (p = 0.01). The female controls showed better working memory (p = 0.01) and auditory attention (p = 0.001) than males. However, we did not find any sex differences in working memory (p = 0.91) or auditory attention (p = 0.93) in the psychosis group. These results are consistent with the presence of sex-modulated cognitive profiles at first presentation of early-onset psychosis.

Long-term consequences of pubertal timing for youth depression: Identifying personal and contextual pathways of risk

PubMed Central

RUDOLPH, KAREN D.; TROOP-GORDON, WENDY; LAMBERT, SHARON F.; NATSUAKI, MISAKI N.

2015-01-01

This research explored sex differences in the pathways linking pubertal timing to depression across 4 years. A sample of 167 youth (M age = 12.41 years, SD = 1.19) and their caregivers completed measures of puberty and semistructured interviews of interpersonal stress and youth depression. Youth reported on psychological (negative self-focus, anxious arousal) and social–behavioral (coping) characteristics; parents reported on youths’ social–behavioral characteristics (withdrawal/social problems) and deviant peer affiliations. Early maturation predicted stable high trajectories of depression in girls; although early maturing boys showed low initial levels of depression, they did not differ from girls by the final wave of the study. Latent growth curve analyses identified several psychological, social–behavioral, and interpersonal pathways accounting for the contribution of pubertal timing to initial and enduring risk for depression in girls as well as emerging risk for depression in boys. These findings provide novel insight into multilevel processes accounting for sex differences in depression across the adolescent transition. PMID:25422971

Transitions in sensitive period attachment learning in infancy: the role of corticosterone.

PubMed

Sullivan, Regina M; Holman, Parker J

2010-05-01

Survival of altricial infants, including humans and rats, depends on attachment to the caregiver - a process that requires infants to recognize, learn, and remember their attachment figure. The demands of a dynamic environment combined with a maturing organism require frequent neurobehavioral reorganization. This restructuring of behavior and its supporting neural circuitry can be viewed through the unique lens of attachment learning in rats in which preference learning is enhanced and aversion learning is attenuated. Behavioral restructuring is well adapted to securing the crucial infant-caregiver relationship regardless of the quality of care. With maturation and the end of the infant-caregiver attachment learning period, the complex interplay of neural structures, hormones, and social behavior coordinates the developing rat's eventual transition to life outside of the nest. Nevertheless, early-life environmental and physiological stressors can alter the resilient nature of this system, particularly with respect to the amygdala, and these changes may provide important clues to understanding the lasting effects of early stress. (c) 2009 Elsevier Ltd. All rights reserved.

Mycotoxin Cocktail in the Samples of Oilseed Cake from Early Maturing Cotton Varieties Associated with Cattle Feeding Problems.

PubMed

Yunus, Agha W; Sulyok, Michael; Böhm, Josef

2015-06-12

Cottonseed cake in South East Asia has been associated with health issues in ruminants in the recent years. The present study was carried out to investigate the health issues associated with cottonseed cake feeding in dairy animals in Pakistan. All the cake samples were confirmed to be from early maturing cotton varieties (maturing prior to or during Monsoon). A survey of the resource persons indicated that the feeding problems with cottonseed cake appeared after 4-5 months of post-production storage. All the cake samples had heavy bacterial counts, and contaminated with over a dozen different fungal genera. Screening for toxins revealed co-contamination with toxic levels of nearly a dozen mycotoxins including aflatoxin B1 + B2 (556 to 5574 ppb), ochratoxin A + B (47 to 2335 ppb), cyclopiazonic acid (1090 to 6706 ppb), equisetin (2226 to 12672 ppb), rubrofusarin (81 to 1125), tenuazonic acid (549 to 9882 ppb), 3-nitropropionic acid (111 to 1032 ppb), and citrinin (29 to 359 ppb). Two buffalo calves in a diagnostic feed trial also showed signs of complex toxicity. These results indicate that inappropriate processing and storage of the cake, in the typical conditions of the subcontinent, could be the main contributory factors regarding the low quality of cottonseed cake.

Do mature forest birds prefer early-successional habitat during the post-fledging period?

Treesearch

Carlin C. Chandler; David I. King; Richard B. Chandler

2012-01-01

Recent studies have highlighted the importance of the post-fledging period to bird populations, suggesting that the importance of this portion of the life cycle is equal to or greater than the nesting period. Nevertheless, few studies have compared abundance of forest nesting species between mature forest and early-successional habitats while controlling for...

CLP1 founder mutation links tRNA splicing and maturation to cerebellar development and neurodegeneration.

PubMed

Schaffer, Ashleigh E; Eggens, Veerle R C; Caglayan, Ahmet Okay; Reuter, Miriam S; Scott, Eric; Coufal, Nicole G; Silhavy, Jennifer L; Xue, Yuanchao; Kayserili, Hulya; Yasuno, Katsuhito; Rosti, Rasim Ozgur; Abdellateef, Mostafa; Caglar, Caner; Kasher, Paul R; Cazemier, J Leonie; Weterman, Marian A; Cantagrel, Vincent; Cai, Na; Zweier, Christiane; Altunoglu, Umut; Satkin, N Bilge; Aktar, Fesih; Tuysuz, Beyhan; Yalcinkaya, Cengiz; Caksen, Huseyin; Bilguvar, Kaya; Fu, Xiang-Dong; Trotta, Christopher R; Gabriel, Stacey; Reis, André; Gunel, Murat; Baas, Frank; Gleeson, Joseph G

2014-04-24

Neurodegenerative diseases can occur so early as to affect neurodevelopment. From a cohort of more than 2,000 consanguineous families with childhood neurological disease, we identified a founder mutation in four independent pedigrees in cleavage and polyadenylation factor I subunit 1 (CLP1). CLP1 is a multifunctional kinase implicated in tRNA, mRNA, and siRNA maturation. Kinase activity of the CLP1 mutant protein was defective, and the tRNA endonuclease complex (TSEN) was destabilized, resulting in impaired pre-tRNA cleavage. Germline clp1 null zebrafish showed cerebellar neurodegeneration that was rescued by wild-type, but not mutant, human CLP1 expression. Patient-derived induced neurons displayed both depletion of mature tRNAs and accumulation of unspliced pre-tRNAs. Transfection of partially processed tRNA fragments into patient cells exacerbated an oxidative stress-induced reduction in cell survival. Our data link tRNA maturation to neuronal development and neurodegeneration through defective CLP1 function in humans. Copyright © 2014 Elsevier Inc. All rights reserved.

A beta-galactosidase gene is expressed during mature fruit abscission of 'Valencia' orange (Citrus sinensis).

PubMed

Wu, Zhencai; Burns, Jacqueline K

2004-07-01

beta-galactosidases have been detected in a wide range of plants and are characterized by their ability to hydrolyse terminal non-reducing beta-D-galactosyl residues from beta-D-galactosides. These enzymes have been detected in a wide range of plant organs and tissues. In a search for differentially expressed genes during the abscission process in citrus, sequences encoding beta-galactosidase were identified. Three cDNA fragments of a beta-galactosidase gene were isolated from a cDNA subtraction library constructed from mature fruit abscission zones 48 h after the application of a mature fruit-specific abscission agent, 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMN-pyrazole). Based on sequence information derived from these fragments, a full-length cDNA of 2847 nucleotides (GenBank accession number AY029198) encoding beta-galactosidase was isolated from mature fruit abscission zones by 5'- and 3'-RACE approaches. The beta-galactosidase cDNA encoded a protein of 737 amino acid residues with a calculated molecular weight of 82 kDa. The deduced protein was highly homologous to plant beta-galactosidases expressed in fruit ripening. Southern blot analysis demonstrated that at least two closely related beta-galactosidase genes were present in 'Valencia' orange. Temporal expression patterns in mature fruit abscission zones indicated beta-galactosidase mRNA was detected 48 h after treatment of CMN-pyrazole and ethephon in mature fruit abscission zones. beta-galactosidase transcripts were detected in leaf abscission zones only after ethephon application. The citrus beta-galactosidase was expressed in stamens and petals of fully opened flowers and young fruitlets. The results suggest that this beta-galactosidase may play a role during abscission as well as early growth and development processes in flowers and fruitlets.

Early IGF-1 primes visual cortex maturation and accelerates developmental switch between NKCC1 and KCC2 chloride transporters in enriched animals.

PubMed

Baroncelli, Laura; Cenni, Maria Cristina; Melani, Riccardo; Deidda, Gabriele; Landi, Silvia; Narducci, Roberta; Cancedda, Laura; Maffei, Lamberto; Berardi, Nicoletta

2017-02-01

Environmental enrichment (EE) has a remarkable impact on brain development. Continuous exposure to EE from birth determines a significant acceleration of visual system maturation both at retinal and cortical levels. A pre-weaning enriched experience is sufficient to trigger the accelerated maturation of the visual system, suggesting that factors affected by EE during the first days of life might prime visual circuits towards a faster development. The search for such factors is crucial not only to gain a better understanding of the molecular hierarchy of brain development but also to identify molecular pathways amenable to be targeted to correct atypical brain developmental trajectories. Here, we showed that IGF-1 levels are increased in the visual cortex of EE rats as early as P6 and this is a crucial event for setting in motion the developmental program induced by EE. Early intracerebroventricular (i.c.v.) infusion of IGF-1 in standard rats was sufficient to mimic the action of EE on visual acuity development, whereas blocking IGF-1 signaling by i.c.v. injections of the IGF-1 receptor antagonist JB1 prevented the deployment of EE effects. Early IGF-1 decreased the ratio between the expression of NKCC1 and KCC2 cation/chloride transporters, and the reversal potential for GABA A R-driven Cl - currents (E Cl ) was shifted toward more negative potentials, indicating that IGF-1 is a crucial factor in accelerating the maturation of GABAergic neurotransmission and promoting the developmental switch of GABA polarity from excitation to inhibition. In addition, early IGF-1 promoted a later occurring increase in its own expression, suggesting a priming effect of early IGF-1 in driving post-weaning cortical maturation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermal maturity of northern Appalachian Basin Devonian shales: Insights from sterane and terpane biomarkers

USGS Publications Warehouse

Hackley, Paul C.; Ryder, Robert T.; Trippi, Michael H.; Alimi, Hossein

2013-01-01

To better estimate thermal maturity of Devonian shales in the northern Appalachian Basin, eleven samples of Marcellus and Huron Shale were characterized via multiple analytical techniques. Vitrinite reflectance, Rock–Eval pyrolysis, gas chromatography (GC) of whole rock extracts, and GC–mass spectrometry (GCMS) of extract saturate fractions were evaluated on three transects that lie across previously documented regional thermal maturity isolines. Results from vitrinite reflectance suggest that most samples are immature with respect to hydrocarbon generation. However, bulk geochemical data and sterane and terpane biomarker ratios from GCMS suggest that almost all samples are in the oil window. This observation is consistent with the presence of thermogenic gas in the study area and higher vitrinite reflectance values recorded from overlying Pennsylvanian coals. These results suggest that vitrinite reflectance is a poor predictor of thermal maturity in early mature areas of Devonian shale, perhaps because reported measurements often include determinations of solid bitumen reflectance. Vitrinite reflectance interpretations in areas of early mature Devonian shale should be supplanted by evaluation of thermal maturity information from biomarker ratios and bulk geochemical data.

Diffusion tensor imaging assessment of brain white matter maturation during the first postnatal year.

PubMed

Provenzale, James M; Liang, Luxia; DeLong, David; White, Leonard E

2007-08-01

The purpose of this study was to use diffusion-weighted and diffusion tensor imaging to investigate the status of cerebral white matter (WM) at term gestation and the rate of WM maturation throughout the first year of life in healthy infants. Fifty-three children (35 boys) ranging in age from 1.5 weeks premature to 51.5 weeks (mean age, 22.9 weeks) underwent conventional MRI, diffusion imaging in three directions (b = 1,000 s/mm2), and diffusion tensor imaging with gradient encoding in six directions, all on a 1.5-T MRI system. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured in three deep WM structures (posterior limb of internal capsule, genu, and splenium of corpus callosum) and two peripheral WM regions (associational WM underlying prefrontal and posterior parietal cortex) with a standard region of interest (44 +/- 4 cm2). ADC and FA were expressed as a percentage of corresponding values measured in a group of healthy young adults. Mean ADC and FA values for deep and peripheral WM were plotted against gestational age normalized to term. The data were fit best with a broken-line linear regression model with a breakpoint at 100 days. ADC and FA values at term were estimated according to the intercept of the initial linear period (before day 100) with day 0. The slope of the linear fits was used to determine the rate of WM maturation in both the early and the late (after day 100) periods. Multivariate analysis of variance tests were used to compare deep and peripheral WM structures at term and at representative early and late ages (days 30 and 200) and to compare rates of ADC and FA maturation in early and late periods within the first year. At term, peripheral WM was less mature than deep WM according to results of extrapolation of ADC and FA values in the first 100 days of life to day 0 (p < 0.01). Mean ADC and FA value (percentage of mean adult value) for peripheral WM were 1.32 x 10(-3) mm2/s (163%) and 0.16 (32%), respectively, and 1.09 x 10(-3) mm2/s (143%) and 0.36 (54%), respectively, for deep WM. On day 30 and day 200, estimated mean ADC and FA continued to show greater diffusion (higher ADC) and less anisotropy (lower FA value) in peripheral WM (p <0.01). During the first year of postnatal life, both ADC and FA matured at higher rates before postnatal day 100 compared with a later time. Differences were observed in rates of maturation in the first 100 days when rates of decrease in ADC and increase in FA were compared between peripheral WM and deep WM; however, the maturational trends differed whether ADC or FA was examined. The early rate of ADC decrease (maturation) was twice as great for peripheral WM than for deep WM (p < 0.01) unexpectedly, but the opposite pattern was observed for FA. The early rate of FA increase (maturation) was approximately one half as great for peripheral WM as for deep WM (p = 0.01). Throughout the rest of the first year, no differences were observed in the rates of change in either index between peripheral WM and deep WM. At term, both ADC and FA differ significantly in peripheral WM and deep WM, deep WM structures being more mature. Both deep WM and peripheral WM mature more rapidly during approximately the first 3 months in comparison with the rest of the first year. Unexpected differences in early (first 100 days) rates of maturation assessed with diffusion-weighted (ADC) and diffusion tensor (FA) imaging suggest that these two techniques may be sensitive to different aspects of WM maturation in the early perinatal period.

Biological Maturation in Adolescence and the Development of Drinking Habits and Alcohol Abuse among Young Males: A Prospective Longitudinal Study.

ERIC Educational Resources Information Center

Andersson, Tommy; Magnusson, David

1990-01-01

The relationship between biological maturation, as evidenced by skeletal growth, during adolescence and the development of drinking habits and alcohol abuse was studied for a representative group of Swedish males (N=88). Early and late maturers had more advanced drinking habits at age 14 years than did normally maturing subjects. (TJH)

COPI selectively drives maturation of the early Golgi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Papanikou, Effrosyni; Day, Kasey J.; Austin, II, Jotham

COPI coated vesicles carry material between Golgi compartments, but the role of COPI in the secretory pathway has been ambiguous. Previous studies of thermosensitive yeast COPI mutants yielded the surprising conclusion that COPI was dispensable both for the secretion of certain proteins and for Golgi cisternal maturation. To revisit these issues, we optimized the anchor-away method, which allows peripheral membrane proteins such as COPI to be sequestered rapidly by adding rapamycin. Video fluorescence microscopy revealed that COPI inactivation causes an early Golgi protein to remain in place while late Golgi proteins undergo cycles of arrival and departure. These dynamics generatemore » partially functional hybrid Golgi structures that contain both early and late Golgi proteins, explaining how secretion can persist when COPI has been inactivated. Lastly, our findings suggest that cisternal maturation involves a COPI-dependent pathway that recycles early Golgi proteins, followed by multiple COPI-independent pathways that recycle late Golgi proteins.« less

COPI selectively drives maturation of the early Golgi

DOE PAGES

Papanikou, Effrosyni; Day, Kasey J.; Austin, II, Jotham; ...

2015-12-28

COPI coated vesicles carry material between Golgi compartments, but the role of COPI in the secretory pathway has been ambiguous. Previous studies of thermosensitive yeast COPI mutants yielded the surprising conclusion that COPI was dispensable both for the secretion of certain proteins and for Golgi cisternal maturation. To revisit these issues, we optimized the anchor-away method, which allows peripheral membrane proteins such as COPI to be sequestered rapidly by adding rapamycin. Video fluorescence microscopy revealed that COPI inactivation causes an early Golgi protein to remain in place while late Golgi proteins undergo cycles of arrival and departure. These dynamics generatemore » partially functional hybrid Golgi structures that contain both early and late Golgi proteins, explaining how secretion can persist when COPI has been inactivated. Lastly, our findings suggest that cisternal maturation involves a COPI-dependent pathway that recycles early Golgi proteins, followed by multiple COPI-independent pathways that recycle late Golgi proteins.« less

Diazocyte development in the marine diazotrophic cyanobacterium Trichodesmium.

PubMed

Sandh, Gustaf; Xu, Linghua; Bergman, Birgitta

2012-02-01

The establishment of non-diazotrophic cultures of the filamentous marine cyanobacterium Trichodesmium erythraeum IMS101 enabled the first detailed investigation of the process leading to the development of its unique nitrogen-fixing cell type, the diazocyte. Trichome heterogeneity was apparent already within 3-8 h, while the differentiation of mature diazocytes, containing the nitrogenase enzyme, required 27 h after the removal of combined nitrogen. The distribution of 'pro-diazocytes' within the trichomes correlates with the localization of mature diazocytes, which suggests that pattern regulation is an early event during diazocyte development. The development was initially identified as changes in the subcellular ultrastructure, most notably the degradation of glycogen granules and gas vacuoles. These changes were preceded by the induced expression of the global nitrogen regulator ntcA at an early stage of combined nitrogen deprivation, followed by elevated expression of genes related to nitrogen metabolism and their corresponding proteins. The strongest induction (10-fold) was related to the transcription of the respiratory gene coxB2, apparent already at an early stage, which suggests an important role for respiration and the subsequent energy generation in the subcellular changes found, and in the creation of the reducing environment required for nitrogen fixation in diazocytes.

[Containing, right hemisphere: projective identification as an interpersonal mechanism, the ability for affect regulation].

PubMed

Becker, Tobias; Streeck-Fischer, Annette

2012-01-01

The capacity of affect regulation develops with priority in reciprocal, non-verbal communication processes between the early caregiver and the baby. In this process, the projective identification plays the role of crucial means of communication. Processes of projective identification which emerge in therapeutic and educational interactions can be understood as such an early form of communication which contributes to the afterward-ripening of the capacity of affect regulation. Before the background of recent neuro-psychological findings it becomes clear, why the reciprocal and non-verbal communication between the early caregiver and infant as well as between the therapist and the patient is of such fundamental importance for the structural (re-) maturation of the right cerebral hemisphere, as well as for the connections between the left and right hemisphere. In case the projective identification persists as a defensive strategy in dealing with other people, pathological interaction circles can develop which can be overcome only when, for example, the other person assumes the role of the "regulating other".

Sage Russet: A new high yielding dual-purpose russet variety, with cold-sweetening resistance, high vitamin C and protein contents and excellent fresh pack and processing potential

USDA-ARS?s Scientific Manuscript database

Sage Russet was released in 2009 by Oregon State University, in cooperation with the USDA-ARS and the Agricultural Experiment Stations of Idaho and Washington. It is a product of the Northwest Potato Variety (Tri-State) Development Program. Sage Russet has a medium-early maturity and produces long, ...

Responses to novel odors mediate maternal behavior and concaveation in gerbils.

PubMed

Clark, M M; Spencer, C A; Galef, B G

1986-01-01

In a series of three experiments we examined: (Experiment 1) responses to novel odors by early- and late-maturing not-pregnant, pregnant, nursing and postweaning female Mongolian gerbils, (Experiment 2) the response of the same eight groups of female gerbils to unfamiliar pups, and (Experiment 3) the rate of induction of maternal behavior by concaveation in early- and late-maturing nulliparous gerbils. We found: (1) that those females that responded relatively positively to novel odors in Experiment 1 were more likely to retrieve and less likely to attack unfamiliar pups in Experiment 2 than those females responding relatively negatively to novel odors in Experiment 1, and (2) that early-maturing nulliparous gerbils both responded more positively to novel odors and exhibited more rapid induction of maternal behavior by concaveation than late-maturing nulliparous gerbils. The results both confirm and extend Fleming and Rosenblatt's (1974) hypothesis that differences in response to novel odors mediate individual differences in maternal responsiveness.

No childhood development of viewpoint-invariant face recognition: evidence from 8-year-olds and adults.

PubMed

Crookes, Kate; Robbins, Rachel A

2014-10-01

Performance on laboratory face tasks improves across childhood, not reaching adult levels until adolescence. Debate surrounds the source of this development, with recent reviews suggesting that underlying face processing mechanisms are mature early in childhood and that the improvement seen on experimental tasks instead results from general cognitive/perceptual development. One face processing mechanism that has been argued to develop slowly is the ability to encode faces in a view-invariant manner (i.e., allowing recognition across changes in viewpoint). However, many previous studies have not controlled for general cognitive factors. In the current study, 8-year-olds and adults performed a recognition memory task with two study-test viewpoint conditions: same view (study front view, test front view) and change view (study front view, test three-quarter view). To allow quantitative comparison between children and adults, performance in the same view condition was matched across the groups by increasing the learning set size for adults. Results showed poorer memory in the change view condition than in the same view condition for both adults and children. Importantly, there was no quantitative difference between children and adults in the size of decrement in memory performance resulting from a change in viewpoint. This finding adds to growing evidence that face processing mechanisms are mature early in childhood. Copyright © 2014 Elsevier Inc. All rights reserved.

Emergence, development, and maturity of the gonad of two species of chitons "sea cockroach" (Mollusca: Polyplacophora) through the early life stages.

PubMed

Avila-Poveda, Omar Hernando; Abadia-Chanona, Quetzalli Yasú

2013-01-01

This study describes and recognises, using histological and microscopical examinations on a morphometrical basis, several gonad traits through the early life stages of Chiton articulatus and C. albolineatus. Gonadal ontogenesis, gonad development stages, sexual differentiation, onset of the first sexual maturity, and growth sequences or "early life stages" were determined. In addition, allometry between lengths and body weight pooled for both sexes per each chiton were calculated using equation Y = aX(b) . A total of 125 chitons (4≤TL≤40 mm, in total length "TL") were used. All allometric relations showed a strong positive correlation (r), close to 1, with b-values above three, indicating an isometric growth. Gonadal ontogenesis and gonad development stages were categorised into three periods ("Pw" without gonad, "Pe" gonad emergence, and "Pf" gonadal sac formed) and four stages ("S0" gametocytogenesis, "S1" gametogenesis, "S2" mature, and "S3" spawning), respectively. Compound digital images were attained for each process. Periods and stages are overlapped among them and between species, with the following overall confidence intervals in TL: Pw 6.13-14.32 mm, Pe 10.32-16.93 mm, Pf 12.99-25.01 mm, S0 16.08-24.34 mm (females) and 19.51-26.60 mm (males), S1 27.15-35.63 mm (females) and 23.45-32.27 mm (males), S2 24.48-40.24 mm (females) and 25.45-32.87 mm (males). Sexual differentiation (in S0) of both chitons occurs first as a female then as a male; although, males reach the onset of the first sexual maturity earlier than females, thus for C. articulatus males at 17 mm and females at 32 mm, and for C. albolineatus males at 23.5 mm and females at 28 mm, all in TL. Four early life stages (i.e., subjuvenile, juvenile, subadult, and adult) are described and proposed to distinguish growth sequences. Our results may be useful to diverse disciplines, from developmental biology to fisheries management.

Maturation of EEG Power Spectra in Early Adolescence: A Longitudinal Study

ERIC Educational Resources Information Center

Cragg, Lucy; Kovacevic, Natasa; McIntosh, Anthony Randal; Poulsen, Catherine; Martinu, Kristina; Leonard, Gabriel; Paus, Tomas

2011-01-01

This study investigated the fine-grained development of the EEG power spectra in early adolescence, and the extent to which it is reflected in changes in peak frequency. It also sought to determine whether sex differences in the EEG power spectra reflect differential patterns of maturation. A group of 56 adolescents were tested at age 10 years and…

A Longitudinal Examination of the Influence of Maturation on Physical Self-Perceptions and the Relationship with Physical Activity in Early Adolescent Girls

ERIC Educational Resources Information Center

Knowles, Ann-Marie; Niven, Ailsa G.; Fawkner, Samantha G.; Henretty, Joan M.

2009-01-01

This longitudinal study investigated the influence of maturation on physical self-perceptions and the relationship with physical activity in early adolescent girls (N = 150; mean age = 12.79 plus or minus 0.31). Physical characteristics were measured and participants completed the Physical Activity Questionnaire for Children, the Children and…

CTCF counter-regulates cardiomyocyte development and maturation programs in the embryonic heart.

PubMed

Gomez-Velazquez, Melisa; Badia-Careaga, Claudio; Lechuga-Vieco, Ana Victoria; Nieto-Arellano, Rocio; Tena, Juan J; Rollan, Isabel; Alvarez, Alba; Torroja, Carlos; Caceres, Eva F; Roy, Anna R; Galjart, Niels; Delgado-Olguin, Paul; Sanchez-Cabo, Fatima; Enriquez, Jose Antonio; Gomez-Skarmeta, Jose Luis; Manzanares, Miguel

2017-08-01

Cardiac progenitors are specified early in development and progressively differentiate and mature into fully functional cardiomyocytes. This process is controlled by an extensively studied transcriptional program. However, the regulatory events coordinating the progression of such program from development to maturation are largely unknown. Here, we show that the genome organizer CTCF is essential for cardiogenesis and that it mediates genomic interactions to coordinate cardiomyocyte differentiation and maturation in the developing heart. Inactivation of Ctcf in cardiac progenitor cells and their derivatives in vivo during development caused severe cardiac defects and death at embryonic day 12.5. Genome wide expression analysis in Ctcf mutant hearts revealed that genes controlling mitochondrial function and protein production, required for cardiomyocyte maturation, were upregulated. However, mitochondria from mutant cardiomyocytes do not mature properly. In contrast, multiple development regulatory genes near predicted heart enhancers, including genes in the IrxA cluster, were downregulated in Ctcf mutants, suggesting that CTCF promotes cardiomyocyte differentiation by facilitating enhancer-promoter interactions. Accordingly, loss of CTCF disrupts gene expression and chromatin interactions as shown by chromatin conformation capture followed by deep sequencing. Furthermore, CRISPR-mediated deletion of an intergenic CTCF site within the IrxA cluster alters gene expression in the developing heart. Thus, CTCF mediates local regulatory interactions to coordinate transcriptional programs controlling transitions in morphology and function during heart development.

CTCF counter-regulates cardiomyocyte development and maturation programs in the embryonic heart

PubMed Central

Gomez-Velazquez, Melisa; Badia-Careaga, Claudio; Lechuga-Vieco, Ana Victoria; Nieto-Arellano, Rocio; Rollan, Isabel; Alvarez, Alba; Torroja, Carlos; Caceres, Eva F.; Roy, Anna R.; Galjart, Niels; Sanchez-Cabo, Fatima; Enriquez, Jose Antonio; Gomez-Skarmeta, Jose Luis

2017-01-01

Cardiac progenitors are specified early in development and progressively differentiate and mature into fully functional cardiomyocytes. This process is controlled by an extensively studied transcriptional program. However, the regulatory events coordinating the progression of such program from development to maturation are largely unknown. Here, we show that the genome organizer CTCF is essential for cardiogenesis and that it mediates genomic interactions to coordinate cardiomyocyte differentiation and maturation in the developing heart. Inactivation of Ctcf in cardiac progenitor cells and their derivatives in vivo during development caused severe cardiac defects and death at embryonic day 12.5. Genome wide expression analysis in Ctcf mutant hearts revealed that genes controlling mitochondrial function and protein production, required for cardiomyocyte maturation, were upregulated. However, mitochondria from mutant cardiomyocytes do not mature properly. In contrast, multiple development regulatory genes near predicted heart enhancers, including genes in the IrxA cluster, were downregulated in Ctcf mutants, suggesting that CTCF promotes cardiomyocyte differentiation by facilitating enhancer-promoter interactions. Accordingly, loss of CTCF disrupts gene expression and chromatin interactions as shown by chromatin conformation capture followed by deep sequencing. Furthermore, CRISPR-mediated deletion of an intergenic CTCF site within the IrxA cluster alters gene expression in the developing heart. Thus, CTCF mediates local regulatory interactions to coordinate transcriptional programs controlling transitions in morphology and function during heart development. PMID:28846746

Effect of selection for growth rate on relative growth in rabbits.

PubMed

Pascual, M; Pla, M; Blasco, A

2008-12-01

The effect of selection for growth rate on relative growth of the rabbit body components was studied. Animals from the 18th generation of a line selected for growth rate were compared with a contemporary control group formed with offspring of embryos that were frozen at the seventh generation of selection of the same line. A total of 313 animals were slaughtered at 4, 9, 13, 20, and 40 wk old. The offal, organs, tissues, and retail cuts were weighed, and several carcass linear measurements were recorded. Huxley's allometric equations relating the weights of the components with respect to BW were fitted. Butterfield's quadratic equations relating the degree of maturity of the components and the degree of maturity of BW were also fitted. In most of the components studied, both models lead to similar patterns of growth. Blood was isometric or early maturing and skin was late maturing or isometric depending on the use of Huxley's or Butterfield's model. Full gastrointestinal tract, liver, kidneys, thoracic viscera, and head were early maturing, and the chilled carcass and reference carcass were late maturing. The retail cuts of the reference carcass showed isometry (forelegs) or late maturing growth (breast and ribs, loin, hind legs, and abdominal walls). Dissectible fat of the carcass and meat of the hind leg had a late development, whereas bone of the hind leg was early maturing. Lumbar circumference length was later maturing than the carcass length and thigh length. Sex did not affect the relative growth of most of the components. Butterfield's model showed that males had an earlier development of full gastrointestinal tract and later growth of kidneys than females. No effect of selection on the relative growth of any of the components studied was found, leading to similar patterns of growth and similar carcass composition at a given degree of maturity after 11 generations of selection for growth rate.

Exploring the Early Organization and Maturation of Linguistic Pathways in the Human Infant Brain.

PubMed

Dubois, Jessica; Poupon, Cyril; Thirion, Bertrand; Simonnet, Hina; Kulikova, Sofya; Leroy, François; Hertz-Pannier, Lucie; Dehaene-Lambertz, Ghislaine

2016-05-01

Linguistic processing is based on a close collaboration between temporal and frontal regions connected by two pathways: the "dorsal" and "ventral pathways" (assumed to support phonological and semantic processing, respectively, in adults). We investigated here the development of these pathways at the onset of language acquisition, during the first post-natal weeks, using cross-sectional diffusion imaging in 21 healthy infants (6-22 weeks of age) and 17 young adults. We compared the bundle organization and microstructure at these two ages using tractography and original clustering analyses of diffusion tensor imaging parameters. We observed structural similarities between both groups, especially concerning the dorsal/ventral pathway segregation and the arcuate fasciculus asymmetry. We further highlighted the developmental tempos of the linguistic bundles: The ventral pathway maturation was more advanced than the dorsal pathway maturation, but the latter catches up during the first post-natal months. Its fast development during this period might relate to the learning of speech cross-modal representations and to the first combinatorial analyses of the speech input. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Biological maturity-associated variance in peak power output and momentum in academy rugby union players.

PubMed

Howard, Sean M A; Cumming, Sean P; Atkinson, Mark; Malina, Robert M

2016-11-01

The study aimed to evaluate the mediating effect of biological maturation on anthropometrical measurements, performance indicators and subsequent selection in a group of academy rugby union players. Fifty-one male players 14-17 years of age were assessed for height, weight and BMI, and percentage of predicted mature status attained at the time of observation was used as an indicator of maturity status. Following this, initial sprint velocity (ISV), Wattbike peak power output (PPO) and initial sprint momentum (ISM) were assessed. A bias towards on-time (n = 44) and early (n = 7) maturers was evident in the total sample and magnified with age cohort. Relative to UK reference values, weight and height were above the 90th and 75th centiles, respectively. Significant (p ≤ .01) correlations were observed between maturity status and BMI (r = .48), weight (r = .63) and height (r = .48). Regression analysis (controlling for age) revealed that maturity status and height explained 68% of ISM variance; however, including BMI in the model attenuated the influence of maturity status below statistical significance (p = .72). Height and BMI explained 51% of PPO variance, while no initial significant predictors were identified for ISV. The sample consisted of players who were on-time and early in maturation with no late maturers represented. This was attributable, in part, to the mediating effect of maturation on body size, which, in turn, predicted performance variables.

Maturation of the Infant Respiratory Microbiota, Environmental Drivers, and Health Consequences. A Prospective Cohort Study.

PubMed

Bosch, Astrid A T M; de Steenhuijsen Piters, Wouter A A; van Houten, Marlies A; Chu, Mei Ling J N; Biesbroek, Giske; Kool, Jolanda; Pernet, Paula; de Groot, Pieter-Kees C M; Eijkemans, Marinus J C; Keijser, Bart J F; Sanders, Elisabeth A M; Bogaert, Debby

2017-12-15

Perinatal and postnatal influences are presumed important drivers of the early-life respiratory microbiota composition. We hypothesized that the respiratory microbiota composition and development in infancy is affecting microbiota stability and thereby resistance against respiratory tract infections (RTIs) over time. To investigate common environmental drivers, including birth mode, feeding type, antibiotic exposure, and crowding conditions, in relation to respiratory tract microbiota maturation and stability, and consecutive risk of RTIs over the first year of life. In a prospectively followed cohort of 112 infants, we characterized the nasopharyngeal microbiota longitudinally from birth on (11 consecutive sample moments and the maximum three RTI samples per subject; in total, n = 1,121 samples) by 16S-rRNA gene amplicon sequencing. Using a microbiota-based machine-learning algorithm, we found that children experiencing a higher number of RTIs in the first year of life already demonstrate an aberrant microbial developmental trajectory from the first month of life on as compared with the reference group (0-2 RTIs/yr). The altered microbiota maturation process coincided with decreased microbial community stability, prolonged reduction of Corynebacterium and Dolosigranulum, enrichment of Moraxella very early in life, followed by later enrichment of Neisseria and Prevotella spp. Independent drivers of these aberrant developmental trajectories of respiratory microbiota members were mode of delivery, infant feeding, crowding, and recent antibiotic use. Our results suggest that environmental drivers impact microbiota development and, consequently, resistance against development of RTIs. This supports the idea that microbiota form the mediator between early-life environmental risk factors for and susceptibility to RTIs over the first year of life.

Maturity status of youth football players: a noninvasive estimate.

PubMed

Malina, Robert M; Cumming, Sean P; Morano, Peter J; Barron, Mary; Miller, Susan J

2005-06-01

To estimate the biological maturity status of youth football players 9-14 yr old using a noninvasive method and to compare the body size of players of contrasting status. Subjects were members of youth football teams in two central Michigan communities. Height and weight were measured on 653 boys 8.7-14.6 yr. Heights of biological parents of 582 boys were reported and subsequently adjusted for overestimation. Decimal age, height, and weight of the player and midparent height were used to predict mature (adult) height for the boy. Current height of each player was expressed as a percentage of his predicted mature height to provide an estimate of biological maturity status. Percentage of predicted mature height of each boy was expressed as a z-score to classify players into maturity groups. ANCOVA, controlling for age, was used to compare body size in contrasting maturity groups. Mean percentages of predicted mature height of the players matched those of longitudinal reference samples, but there was a trend for higher percentages among older players, suggesting advanced maturation. Overall, 405 boys were classified as on time/average in maturity status (69.6% [95%CI 65.7-73.3]), 154 were classified as early/advanced (25.5% [95%CI 23.0-30.3]), and only 23 were classified as late/delayed (3.9% [95%CI 2.6-6.0]). The gradient for height, weight, and BMI was as follows: early > on time > late, and differences were greater for weight and the BMI than for height. Percentage of predicted mature height attained at a given age appears to be a reasonable indicator of maturity status. The method needs to be validated with other more direct indicators (skeletal age, sexual maturation) and applied to other samples.

Sex-ratio, seasonality and long-term variation in maturation and spawning of the brown shrimp Crangon crangon (L.) in the German Bight (North Sea)

NASA Astrophysics Data System (ADS)

Siegel, V.; Damm, U.; Neudecker, T.

2008-12-01

Aspects of the reproductive and maturation biology of the brown shrimp Crangon crangon (L.) were studied in various subareas of the German Bight (North Sea). The size-specific sex ratio of C. crangon was examined based on length frequency distribution data. The sex ratio for the smallest size groups at which sex was determined was typically around 0.5, indicating an even ratio between males and females. The proportion of females decreased in the 30-45 mm size range. In length classes larger than 50 mm, the proportion of females constantly increases to 100% at around 60 mm total length. We concluded that sex reversal from male to female may not occur in C. crangon. Size at sexual maturity was determined from the proportion of ovigerous females. Size at maturity ( L 50) was estimated as 55.4 and 62.0 mm total length for spring and winter data, respectively. The seasonal spawning cycle was studied over the period 1958-2005. Between mid February and late June and for size classes larger than 65 mm ovigerous shrimps exceeded 80% and reached up to 100% of the females in the population. This period can be seen as the core spawning season. From early August to early December the proportion of ovigerous shrimps in the female population is very low. Interannual differences in the seasonal process are obvious with a dramatic decline in C. crangon reproductive success in the late 1980s. Various options are discussed for the reasons of the decline and recovery of the reproductive performance.

Poor sleep quality predicts deficient emotion information processing over time in early adolescence.

PubMed

Soffer-Dudek, Nirit; Sadeh, Avi; Dahl, Ronald E; Rosenblat-Stein, Shiran

2011-11-01

There is deepening understanding of the effects of sleep on emotional information processing. Emotion information processing is a key aspect of social competence, which undergoes important maturational and developmental changes in adolescence; however, most research in this area has focused on adults. Our aim was to test the links between sleep and emotion information processing during early adolescence. Sleep and facial information processing were assessed objectively during 3 assessment waves, separated by 1-year lags. Data were obtained in natural environments-sleep was assessed in home settings, and facial information processing was assessed at school. 94 healthy children (53 girls, 41 boys), aged 10 years at Time 1. N/A. Facial information processing was tested under neutral (gender identification) and emotional (emotional expression identification) conditions. Sleep was assessed in home settings using actigraphy for 7 nights at each assessment wave. Waking > 5 min was considered a night awakening. Using multilevel modeling, elevated night awakenings and decreased sleep efficiency significantly predicted poor performance only in the emotional information processing condition (e.g., b = -1.79, SD = 0.52, confidence interval: lower boundary = -2.82, upper boundary = -0.076, t(416.94) = -3.42, P = 0.001). Poor sleep quality is associated with compromised emotional information processing during early adolescence, a sensitive period in socio-emotional development.

The mating brain: early maturing sneaker males maintain investment into the brain also under fast body growth in Atlantic salmon (Salmo salar).

PubMed

Kotrschal, Alexander; Trombley, Susanne; Rogell, Björn; Brannström, Ioana; Foconi, Eric; Schmitz, Monika; Kolm, Niclas

It has been suggested that mating behaviours require high levels of cognitive ability. However, since investment into mating and the brain both are costly features, their relationship is likely characterized by energetic trade-offs. Empirical data on the subject remains equivocal. We investigated if early sexual maturation was associated with brain development in Atlantic salmon ( Salmo salar ), in which males can either stay in the river and sexually mature at a small size (sneaker males) or migrate to the sea and delay sexual maturation until they have grown much larger (anadromous males). Specifically, we tested how sexual maturation may induce plastic changes in brain development by rearing juveniles on either natural or ad libitum feeding levels. After their first season we compared brain size and brain region volumes across both types of male mating tactics and females. Body growth increased greatly across both male mating tactics and females during ad libitum feeding as compared to natural feeding levels. However, despite similar relative increases in body size, early maturing sneaker males maintained larger relative brain size during ad libitum feeding levels as compared to anadromous males and females. We also detected several differences in the relative size of separate brain regions across feeding treatments, sexes and mating strategies. For instance, the relative size of the cognitive centre of the brain, the telencephalon, was largest in sneaker males. Our data support that a large relative brain size is maintained in individuals that start reproduction early also during fast body growth. We propose that the cognitive demands during complex mating behaviours maintain a high level of investment into brain development in reproducing individuals.

Developmental duration and morphology of the sea star asterias amurensis, in tongyeong, Korea

NASA Astrophysics Data System (ADS)

Paik, Sang-Gyu; Park, Heung-Sik; Yi, Soon Kil; Yun, Sung Gyu

2005-09-01

The process of embryogenesis and larval development of the asteroid sea star Asterias amurensis (Lütken) was observed, with special attention paid to morphological change and larval duration. In reproductive season, mature sea stars were collected under floating net cages, located in Tongyeong, southern Korea. The mature eggs are 138 μm in average diameter, semi-translucent and orange in color, sperms in good condition appear light cream to white-gray in color. Embryos develop through the holoblastic equal cleavage stage and a wrinkled blastula stage that lasts about 9 hours after fertilization. Gastrulae bearing an expanded archenteron hatch from the fertilization envelope 22 hours after fertilization. At the end of gastrulation, rudiments of the left and right coelom are formed. By day 2, larvae possess complete alimentary canal and begin to feed. At this stage, the larva is called early bipinnaria. In 6day-old larvae, the pre- and post- oral ciliated bands form complete circuits and the bipinnarial processes start to develop. By day 12, the lateral and anterior projection of the larval wall processes along the ciliated bands begins to thicken and curl, and the ciliated bands become more prominent. By day 32, early brachiolaria are presented with three pairs of brachiolar arms. Advanced brachiolaria with a well-developed brachiolar complex (three pairs of brachia and central adhesive disc) occur 6 weeks after fertilization. In the field, spawning of the sea star was observed in April to May, settlement form larvae and just settlements seem to occur from June to July, and early juveniles occur from August to September. Although we had not described the end of brachiolaria stage, it can be tentatively estimated that the duration of the pelagic stage of A. amurensis is 40 to 50 days.

Objectives and Design of the Hemodialysis Fistula Maturation Study

PubMed Central

Dember, Laura M.; Imrey, Peter B.; Beck, Gerald J.; Cheung, Alfred K.; Himmelfarb, Jonathan; Huber, Thomas S.; Kusek, John W.; Roy-Chaudhury, Prabir; Vazquez, Miguel A.; Alpers, Charles E.; Robbin, Michelle L.; Vita, Joseph A.; Greene, Tom; Gassman, Jennifer J.; Feldman, Harold I.

2014-01-01

Background A large proportion of newly created arteriovenous fistulas cannot be used for dialysis because they fail to mature adequately to support the hemodialysis blood circuit. The Hemodialysis Fistula Maturation (HFM) Study was designed to elucidate clinical and biological factors associated with fistula maturation outcomes. Study Design Multicenter prospective cohort study. Setting & Participants Approximately 600 patients undergoing creation of a new hemodialysis fistula will be enrolled at 7 centers in the United States and followed up for as long as 4 years. Predictors Clinical, anatomical, biological, and process-of-care attributes identified pre-operatively, intra-operatively, or post-operatively. Outcomes The primary outcome is unassisted clinical maturation defined as successful use of the fistula for dialysis for four weeks without any maturation-enhancing procedures. Secondary outcomes include assisted clinical maturation, ultrasound-based anatomical maturation, fistula procedures, fistula abandonment, and central venous catheter use. Measurements Pre-operative ultrasound arterial and venous mapping, flow-mediated and nitroglycerin-mediated brachial artery dilation, arterial pulse wave velocity, and venous distensibility; intra-operative vein tissue collection for histopathological and molecular analyses; post-operative ultrasounds at 1 day, 2 weeks, 6 weeks, and prior to fistula intervention and initial cannulation. Results Assuming complete data, no covariate adjustment, and unassisted clinical maturation of 50%, there will be 80% power to detect ORs of 1.83 and 1.61 for dichotomous predictor variables with exposure prevalences of 20% and 50%, respectively. Limitations Exclusion of two-stage transposition fistulas limits generalizability. The requirement for study visits may result in a cohort that is healthier than the overall population of patients undergoing fistula creation. Conclusions The HFM Study will be of sufficient size and scope to 1) evaluate a broad range of mechanistic hypotheses, 2) identify clinical practices associated with maturation outcomes, 3) assess the predictive utility of early indicators of fistula outcome, and 4) establish targets for novel therapeutic interventions to improve fistula maturation. PMID:23992885

[Influence of different processing methods and mature stages on 3,29-dibenzoyl rarounitriol of Trichosanthes kirilowii seeds].

PubMed

Liu, Jin-Na; Xie, Xiao-Liang; Yang, Tai-Xin; Zhang, Cun-Li; Jia, Dong-Sheng; Liu, Ming; Wen, Chun-Xiu

2014-04-01

To study the different mature stages and the best processing methods on the quality of Trichosanthes kirilowii seeds. The content of 3,29-dibenzoyl rarounitriol in Trichosanthes kirilowii seeds was determined by HPLC. The sample of different mature stages such as immature, near mature and fully mature and processed by different methods were studied. Fully mature Trichosanthes kirilowii seeds were better than the immatured, and the best processing method was dried under 60degrees C, the content of 3,29-dibenzoyl rarounitriol reached up to 131.63microlg/mL. Different processing methods and different mature stages had a significant influence on the quality of Trichosanthes kirilowii seeds.

Elucidating the mechanisms linking early pubertal timing, sexual activity, and substance use for maltreated versus nonmaltreated adolescents

PubMed Central

Negriff, Sonya; Brensilver, Matthew; Trickett, Penelope K.

2015-01-01

Purpose To test models linking pubertal timing, peer substance use, sexual behavior, and substance use for maltreated versus comparison adolescents. Three theoretical mechanisms were tested: 1) peer influence links early pubertal timing to later sexual behavior and substance use, 2) early maturers engage in substance use on their own and then select substance-using friends, or 3) early maturers initiate sexual behaviors which leads them to substance-using peers. Methods The data came from a longitudinal study of the effects of child maltreatment on adolescent development (303 maltreated and 151 comparison adolescents; age: 9–13 years at initial wave). Multiple-group structural equation models tested the hypotheses across three timepoints including variables of pubertal timing, perception of peer substance use, sexual behavior, and self-reported substance use. Results Early pubertal timing was associated with substance-using peers only for maltreated adolescents, indicating the mediation path from early pubertal timing through substance-using peers to subsequent adolescent substance use and sexual behavior only holds for maltreated adolescents. Mediation via sexual behavior was significant for both maltreated and comparison adolescents. This indicates that sexual behavior may be a more universal mechanism linking early maturation with risky friends regardless of adverse life experiences. Conclusions The findings are a step toward elucidating the developmental pathways from early puberty to risk behavior and identifying early experiences that may alter mediation effects. PMID:26003577

Early parental care is important for hippocampal maturation: evidence from brain morphology in humans.

PubMed

Rao, Hengyi; Betancourt, Laura; Giannetta, Joan M; Brodsky, Nancy L; Korczykowski, Marc; Avants, Brian B; Gee, James C; Wang, Jiongjiong; Hurt, Hallam; Detre, John A; Farah, Martha J

2010-01-01

The effects of early life experience on later brain structure and function have been studied extensively in animals, yet the relationship between childhood experience and normal brain development in humans remains largely unknown. Using a unique longitudinal data set including ecologically valid in-home measures of early experience during childhood (at age 4 and 8 years) and high-resolution structural brain imaging during adolescence (mean age 14 years), we examined the effects on later brain morphology of two dimensions of early experience: parental nurturance and environmental stimulation. Parental nurturance at age 4 predicts the volume of the left hippocampus in adolescence, with better nurturance associated with smaller hippocampal volume. In contrast, environmental stimulation did not correlate with hippocampal volume. Moreover, the association between hippocampal volume and parental nurturance disappears at age 8, supporting the existence of a sensitive developmental period for brain maturation. These findings indicate that variation in normal childhood experience is associated with differences in brain morphology, and hippocampal volume is specifically associated with early parental nurturance. Our results provide neuroimaging evidence supporting the important role of warm parental care during early childhood for brain maturation.

Selection occurs within linear fruit and during the early stages of reproduction in Robinia pseudoacacia

PubMed Central

2014-01-01

Background Pollen donor compositions differ during the early stages of reproduction due to various selection mechanisms. In addition, ovules linearly ordered within a fruit have different probabilities of reaching maturity. Few attempts, however, have been made to directly examine the magnitude and timing of selection, as well as the mechanisms during early life stages and within fruit. Robinia pseudoacacia, which contains linear fruit and non-random ovule maturation and abortion patterns, has been used to study the viability of selection within fruit and during the early stages of reproduction. To examine changes in the pollen donor composition during the early stages of reproduction and of progeny originating from different positions within fruit, paternity analyses were performed for three early life stages (aborted seeds, mature seeds and seedlings) in the insect-pollinated tree R. pseudoacacia. Results Selection resulted in an overall decrease in the level of surviving selfed progeny at each life stage. The greatest change was observed between the aborted seed stage and mature seed stage, indicative of inbreeding depression (the reduced fitness of a given population that occurs when related individual breeding was responsible for early selection). A selective advantage was detected among paternal trees. Within fruits, the distal ends showed higher outcrossing rates than the basal ends, indicative of selection based on the order of seeds within the fruit. Conclusions Our results suggest that selection exists both within linear fruit and during the early stages of reproduction, and that this selection can affect male reproductive success during the early life stages. This indicates that tree species with mixed-mating systems may have evolved pollen selection mechanisms to increase the fitness of progeny and adjust the population genetic composition. The early selection that we detected suggests that inbreeding depression caused the high abortion rate and low seed set in R. pseudoacacia. PMID:24655746

Selection occurs within linear fruit and during the early stages of reproduction in Robinia pseudoacacia.

PubMed

Yuan, Cun-Quan; Sun, Yu-Han; Li, Yun-Fei; Zhao, Ke-Qi; Hu, Rui-Yang; Li, Yun

2014-03-21

Pollen donor compositions differ during the early stages of reproduction due to various selection mechanisms. In addition, ovules linearly ordered within a fruit have different probabilities of reaching maturity. Few attempts, however, have been made to directly examine the magnitude and timing of selection, as well as the mechanisms during early life stages and within fruit. Robinia pseudoacacia, which contains linear fruit and non-random ovule maturation and abortion patterns, has been used to study the viability of selection within fruit and during the early stages of reproduction. To examine changes in the pollen donor composition during the early stages of reproduction and of progeny originating from different positions within fruit, paternity analyses were performed for three early life stages (aborted seeds, mature seeds and seedlings) in the insect-pollinated tree R. pseudoacacia. Selection resulted in an overall decrease in the level of surviving selfed progeny at each life stage. The greatest change was observed between the aborted seed stage and mature seed stage, indicative of inbreeding depression (the reduced fitness of a given population that occurs when related individual breeding was responsible for early selection). A selective advantage was detected among paternal trees. Within fruits, the distal ends showed higher outcrossing rates than the basal ends, indicative of selection based on the order of seeds within the fruit. Our results suggest that selection exists both within linear fruit and during the early stages of reproduction, and that this selection can affect male reproductive success during the early life stages. This indicates that tree species with mixed-mating systems may have evolved pollen selection mechanisms to increase the fitness of progeny and adjust the population genetic composition. The early selection that we detected suggests that inbreeding depression caused the high abortion rate and low seed set in R. pseudoacacia.

Knockdown of DISC1 by in utero gene transfer disturbs postnatal dopaminergic maturation in the frontal cortex and leads to adult behavioral deficits

PubMed Central

Niwa, Minae; Kamiya, Atsushi; Murai, Rina; Kubo, Ken-ichiro; Gruber, Aaron J; Tomita, Kenji; Lu, Lingling; Tomisato, Shuta; Jaaro-Peled, Hanna; Seshadri, Saurav; Hiyama, Hideki; Huang, Beverly; Kohda, Kazuhisa; Noda, Yukihiro; O’Donnell, Patricio; Nakajima, Kazunori; Sawa, Akira; Nabeshima, Toshitaka

2011-01-01

SUMMARY Adult brain function and behavior are influenced by neuronal network formation during development. Genetic susceptibility factors for adult psychiatric illnesses, such as Neuregulin-1 and Disrupted-in-Schizophrenia-1 (DISC1), influence adult high brain functions, including cognition and information processing. These factors have roles during neurodevelopment and are likely to cooperate, forming “pathways” or “signalosomes.” Here we report the potential to generate an animal model via in utero gene transfer in order to address an important question of how nonlethal deficits in early development may affect postnatal brain maturation and high brain functions in adulthood, which are impaired in various psychiatric illnesses, such as schizophrenia. We show that transient knockdown of DISC1 in the pre- and peri-natal stages, specifically in a lineage of pyramidal neurons mainly in the prefrontal cortex, leads to selective abnormalities in postnatal mesocortical dopaminergic maturation and behavioral abnormalities associated with disturbed cortical neurocircuitry after puberty. PMID:20188653

White matter maturation is associated with the emergence of Theory of Mind in early childhood

PubMed Central

Grosse Wiesmann, Charlotte; Schreiber, Jan; Singer, Tania; Steinbeis, Nikolaus; Friederici, Angela D.

2017-01-01

The ability to attribute mental states to other individuals is crucial for human cognition. A milestone of this ability is reached around the age of 4, when children start understanding that others can have false beliefs about the world. The neural basis supporting this critical step is currently unknown. Here, we relate this behavioural change to the maturation of white matter structure in 3- and 4-year-old children. Tract-based spatial statistics and probabilistic tractography show that the developmental breakthrough in false belief understanding is associated with age-related changes in local white matter structure in temporoparietal regions, the precuneus and medial prefrontal cortex, and with increased dorsal white matter connectivity between temporoparietal and inferior frontal regions. These effects are independent of co-developing cognitive abilities. Our findings show that the emergence of mental state representation is related to the maturation of core belief processing regions and their connection to the prefrontal cortex. PMID:28322222

BMP Signaling in Astrocytes Downregulates EGFR to Modulate Survival and Maturation

PubMed Central

Scholze, Anja R.; Foo, Lynette C.; Mulinyawe, Sara; Barres, Ben A.

2014-01-01

Astrocytes constitute a major cell population in the brain with a myriad of essential functions, yet we know remarkably little about the signaling pathways and mechanisms that direct astrocyte maturation. To explore the signals regulating astrocyte development, we prospectively purified and cultured immature postnatal rodent astrocytes. We identified fibroblast growth factors (FGFs) and bone morphogenetic proteins (BMPs) as robust trophic factors for immature astrocytes. We showed that astrocytes respond directly to BMPs via phosphorylation of the smad1/5/8 pathway. In vitro, BMP signaling promoted immature astrocytes to adopt multiple characteristics of mature astrocytes, including a more process-bearing morphology, aquaporin-4 (AQP4) and S100β immunoreactivity, limited proliferation, and strong downregulation of epidermal growth factor receptor (EGFR). In vivo, activation of the smad1/5/8 pathway in astrocytes was seen during early postnatal development, but inhibition of astrocyte proliferation was not observed. These insights can aid in the further dissection of the mechanisms and pathways controlling astrocyte biology and development. PMID:25330173

White matter maturation is associated with the emergence of Theory of Mind in early childhood.

PubMed

Grosse Wiesmann, Charlotte; Schreiber, Jan; Singer, Tania; Steinbeis, Nikolaus; Friederici, Angela D

2017-03-21

The ability to attribute mental states to other individuals is crucial for human cognition. A milestone of this ability is reached around the age of 4, when children start understanding that others can have false beliefs about the world. The neural basis supporting this critical step is currently unknown. Here, we relate this behavioural change to the maturation of white matter structure in 3- and 4-year-old children. Tract-based spatial statistics and probabilistic tractography show that the developmental breakthrough in false belief understanding is associated with age-related changes in local white matter structure in temporoparietal regions, the precuneus and medial prefrontal cortex, and with increased dorsal white matter connectivity between temporoparietal and inferior frontal regions. These effects are independent of co-developing cognitive abilities. Our findings show that the emergence of mental state representation is related to the maturation of core belief processing regions and their connection to the prefrontal cortex.

Time varying default barrier as an agreement rules on bond contract

NASA Astrophysics Data System (ADS)

Maruddani, Di Asih I.; Safitri, Diah; Hoyyi, Abdul

2018-05-01

There are some default time rules on contract agreement of a bond. The classical default time is known as Merton Model. The most important characteristic of Merton’s model is the restriction of default time to the maturity of the debt, not taking into consideration the possibility of an early default. If the firm’s value falls down to minimal level before the maturity of the debt, but it is able to recover and meet the debt’s payment at maturity, the default would be avoided in Merton’ s approach. Merton model has been expanded by Hull & White [6] and Avellaneda & Zhu [1]. They introduced time-varying default barrier for modelling distance to default process. This model use time-varying variable as a barrier. In this paper, we give a valuation of a bond with time-varying default barrier agreement. We use straight forward integration for obtaining equity and liability equation. This theory is applied in Indonesian corporate bond.

Partitioning of 13C-photosynthate from Spur Leaves during Fruit Growth of Three Japanese Pear (Pyrus pyrifolia) Cultivars Differing in Maturation Date

PubMed Central

ZHANG, CAIXI; TANABE, KENJI; TAMURA, FUMIO; ITAI, AKIHIRO; WANG, SHIPING

2005-01-01

• Background and Aims In fruit crops, fruit size at harvest is an important aspect of quality. With Japanese pears (Pyrus pyrifolia), later maturing cultivars usually have larger fruits than earlier maturing cultivars. It is considered that the supply of photosynthate during fruit development is a critical determinant of size. To assess the interaction of assimilate supply and early/late maturity of cultivars and its effect on final fruit size, the pattern of carbon assimilate partitioning from spur leaves (source) to fruit and other organs (sinks) during fruit growth was investigated using three genotypes differing in maturation date. • Methods Partitioning of photosynthate from spur leaves during fruit growth was investigated by exposure of spurs to 13CO2 and measurement of the change in 13C abundance in dry matter with time. Leaf number and leaf area per spur, fresh fruit weight, cell number and cell size of the mesocarp were measured and used to model the development of the spur leaf and fruit. • Key Results Compared with the earlier-maturing cultivars ‘Shinsui’ and ‘Kousui’, the larger-fruited, later-maturing cultivar ‘Shinsetsu’ had a greater total leaf area per spur, greater source strength (source weight × source specific activity), with more 13C assimilated per spur and allocated to fruit, smaller loss of 13C in respiration and export over the season, and longer duration of cell division and enlargement. Histology shows that cultivar differences in final fruit size were mainly attributable to the number of cells in the mesocarp. • Conclusions Assimilate availability during the period of cell division was crucial for early fruit growth and closely correlated with final fruit size. Early fruit growth of the earlier-maturing cultivars, but not the later-maturing ones, was severely restrained by assimilate supply rather than by sink limitation. PMID:15655106

COPI selectively drives maturation of the early Golgi

PubMed Central

Papanikou, Effrosyni; Day, Kasey J; Austin, Jotham; Glick, Benjamin S

2015-01-01

COPI coated vesicles carry material between Golgi compartments, but the role of COPI in the secretory pathway has been ambiguous. Previous studies of thermosensitive yeast COPI mutants yielded the surprising conclusion that COPI was dispensable both for the secretion of certain proteins and for Golgi cisternal maturation. To revisit these issues, we optimized the anchor-away method, which allows peripheral membrane proteins such as COPI to be sequestered rapidly by adding rapamycin. Video fluorescence microscopy revealed that COPI inactivation causes an early Golgi protein to remain in place while late Golgi proteins undergo cycles of arrival and departure. These dynamics generate partially functional hybrid Golgi structures that contain both early and late Golgi proteins, explaining how secretion can persist when COPI has been inactivated. Our findings suggest that cisternal maturation involves a COPI-dependent pathway that recycles early Golgi proteins, followed by multiple COPI-independent pathways that recycle late Golgi proteins. DOI: http://dx.doi.org/10.7554/eLife.13232.001 PMID:26709839

Inhibition of GSK3β rescues hippocampal development and learning in a mouse model of CDKL5 disorder.

PubMed

Fuchs, Claudia; Rimondini, Roberto; Viggiano, Rocchina; Trazzi, Stefania; De Franceschi, Marianna; Bartesaghi, Renata; Ciani, Elisabetta

2015-10-01

Mutations in the X-linked cyclin-dependent kinase-like 5 (CDKL5) gene have been identified in a rare neurodevelopmental disorder characterized by early-onset seizures, severe developmental delay, intellectual disability and Rett syndrome-like features. CDKL5 is highly expressed in the brain during early postnatal stages, suggesting its importance for brain maturation. Using a newly-generated Cdkl5 knockout (Cdkl5 -/Y) mouse, we recently found that loss of Cdkl5 impairs postnatal hippocampal development with a reduction in neuronal precursor survival and maturation. These defects were accompanied by increased activity of the glycogen synthase kinase 3β (GSK3β) a crucial inhibitory regulator of many neurodevelopmental processes. The goal of the current study was to establish whether inhibition of GSK3β corrects hippocampal developmental defects due to Cdkl5 loss. We found that treatment with the GSK3β inhibitor SB216763 restored neuronal precursor survival, dendritic maturation, connectivity and hippocampus-dependent learning and memory in the Cdkl5 -/Y mouse. Importantly, these effects were retained one month after treatment cessation. At present, there are no therapeutic strategies to improve the neurological defects of subjects with CDKL5 disorder. Current results point at GSK3β inhibitors as potential therapeutic tools for the improvement of abnormal brain development in CDKL5 disorder. Copyright © 2015. Published by Elsevier Inc.

Impact of warming climate and cultivar change on maize phenology in the last three decades in North China Plain

NASA Astrophysics Data System (ADS)

Xiao, Dengpan; Qi, Yongqing; Shen, Yanjun; Tao, Fulu; Moiwo, Juana P.; Liu, Jianfeng; Wang, Rede; Zhang, He; Liu, Fengshan

2016-05-01

As climate change could significantly influence crop phenology and subsequent crop yield, adaptation is a critical mitigation process of the vulnerability of crop growth and production to climate change. Thus, to ensure crop production and food security, there is the need for research on the natural (shifts in crop growth periods) and artificial (shifts in crop cultivars) modes of crop adaptation to climate change. In this study, field observations in 18 stations in North China Plain (NCP) are used in combination with Agricultural Production Systems Simulator (APSIM)-Maize model to analyze the trends in summer maize phenology in relation to climate change and cultivar shift in 1981-2008. Apparent warming in most of the investigated stations causes early flowering and maturity and consequently shortens reproductive growth stage. However, APSIM-Maize model run for four representative stations suggests that cultivar shift delays maturity and thereby prolongs reproductive growth (flowering to maturity) stage by 2.4-3.7 day per decade (d 10a-1). The study suggests a gradual adaptation of maize production process to ongoing climate change in NCP via shifts in high thermal cultivars and phenological processes. It is concluded that cultivation of maize cultivars with longer growth periods and higher thermal requirements could mitigate the negative effects of warming climate on crop production and food security in the NCP study area and beyond.

Constitutive expression and silencing of a novel seed specific calcium dependent protein kinase gene in rice reveals its role in grain filling.

PubMed

Manimaran, P; Mangrauthia, Satendra K; Sundaram, R M; Balachandran, S M

2015-02-01

Ca(2+) sensor protein kinases are prevalent in most plant species including rice. They play diverse roles in plant signaling mechanism. Thirty one CDPK genes have been identified in rice and some are functionally characterized. In the present study, the newly identified rice CDPK gene OsCPK31 was functionally validated by overexpression and silencing in Taipei 309 rice cultivar. Spikelets of overexpressing plants showed hard dough stage within 15d after pollination (DAP) with rapid grain filling and early maturation. Scanning electron microscopy of endosperm during starch granule formation confirmed early grain filling. Further, seeds of overexpressing transgenic lines matured early (20-22 DAP) and the average number of maturity days reduced significantly. On the other hand, silencing lines showed more number of unfilled spikelet without any difference in maturity duration. It will be interesting to further decipher the role of OsCPK31 in biological pathways associated with distribution of photosynthetic assimilates during grain filling stage. Copyright © 2014 Elsevier GmbH. All rights reserved.

Constraining the thermal history of the North American Midcontinent Rift System using carbonate clumped isotopes and organic thermal maturity indices

USGS Publications Warehouse

Gallagher, Timothy M.; Sheldon, Nathan D.; Mauk, Jeffrey L.; Petersen, Sierra V.; Gueneli, Nur; Brocks, Jochen J.

2017-01-01

The Midcontinent Rift System (MRS) is a Late Mesoproterozoic (∼1.1 Ga) sequence of volcanic and sedimentary rocks exposed in the Lake Superior Region of North America. The MRS continues to be the focus of much research due to its economic mineral deposits as well as its archive of Precambrian life and tectonic processes. In order to constrain the post-depositional thermal history of the MRS, samples were analyzed for carbonate clumped isotope composition and organic thermal maturity. Clumped isotope values from sedimentary/early-diagenetic samples were partially reset during burial to temperatures between 68 and 75 °C. Solid-state reordering models indicate that maximum burial temperatures of 125–155 °C would reset the clumped isotope values to the observed temperature range prior to the onset of regional cooling and uplift. Clumped isotope results from late-stage veins in the White Pine Mine encompass a greater temperature range (49–116 °C), indicative of spatially variable hydrothermal activity and vein emplacement after burial temperatures fell below 100 °C during regional cooling and uplift. Clumped isotope and organic thermal maturity data do not indicate significant spatial differences in thermal history along the MRS. Observed variability in bulk organic matter composition and biomarker indices are therefore more likely a result of shifts in primary productivity or early-degradation processes. These results demonstrate that the MRS experienced a spatially consistent, relatively mild thermal history (125–155 °C) and is therefore a valuable archive for understanding the Late Mesoproterozoic environment.

Repression of osteoblast maturation by ERRα accounts for bone loss induced by estrogen deficiency.

PubMed

Gallet, Marlène; Saïdi, Soraya; Haÿ, Eric; Photsavang, Johann; Marty, Caroline; Sailland, Juliette; Carnesecchi, Julie; Tribollet, Violaine; Barenton, Bruno; Forcet, Christelle; Birling, Marie-Christine; Sorg, Tania; Chassande, Olivier; Cohen-Solal, Martine; Vanacker, Jean-Marc

2013-01-01

ERRα is an orphan member of the nuclear receptor family, the complete inactivation of which confers resistance to bone loss induced by ageing and estrogen withdrawal to female mice in correlation with increased bone formation in vivo. Furthermore ERRα negatively regulates the commitment of mesenchymal cells to the osteoblast lineage ex vivo as well as later steps of osteoblast maturation. We searched to determine whether the activities of ERRα on osteoblast maturation are responsible for one or both types of in vivo induced bone loss. To this end we have generated conditional knock out mice in which the receptor is normally present during early osteoblast differentiation but inactivated upon osteoblast maturation. Bone ageing in these animals was similar to that observed for control animals. In contrast conditional ERRαKO mice were completely resistant to bone loss induced by ovariectomy. We conclude that the late (maturation), but not early (commitment), negative effects of ERRα on the osteoblast lineage contribute to the reduced bone mineral density observed upon estrogen deficiency.

Face recognition ability matures late: evidence from individual differences in young adults.

PubMed

Susilo, Tirta; Germine, Laura; Duchaine, Bradley

2013-10-01

Does face recognition ability mature early in childhood (early maturation hypothesis) or does it continue to develop well into adulthood (late maturation hypothesis)? This fundamental issue in face recognition is typically addressed by comparing child and adult participants. However, the interpretation of such studies is complicated by children's inferior test-taking abilities and general cognitive functions. Here we examined the developmental trajectory of face recognition ability in an individual differences study of 18-33 year-olds (n = 2,032), an age interval in which participants are competent test takers with comparable general cognitive functions. We found a positive association between age and face recognition, controlling for nonface visual recognition, verbal memory, sex, and own-race bias. Our study supports the late maturation hypothesis in face recognition, and illustrates how individual differences investigations of young adults can address theoretical issues concerning the development of perceptual and cognitive abilities. PsycINFO Database Record (c) 2013 APA, all rights reserved.

The first thousand days - intestinal microbiology of early life: establishing a symbiosis.

PubMed

Wopereis, Harm; Oozeer, Raish; Knipping, Karen; Belzer, Clara; Knol, Jan

2014-08-01

The development of the intestinal microbiota in the first years of life is a dynamic process significantly influenced by early-life nutrition. Pioneer bacteria colonizing the infant intestinal tract and the gradual diversification to a stable climax ecosystem plays a crucial role in establishing host-microbe interactions essential for optimal symbiosis. This colonization process and establishment of symbiosis may profoundly influence health throughout life. Recent developments in microbiologic cultivation-independent methods allow a detailed view of the key players and factors involved in this process and may further elucidate their roles in a healthy gut and immune maturation. Aberrant patterns may lead to identifying key microbial signatures involved in developing immunologic diseases into adulthood, such as asthma and atopic diseases. The central role of early-life nutrition in the developmental human microbiota, immunity, and metabolism offers promising strategies for prevention and treatment of such diseases. This review provides an overview of the development of the intestinal microbiota, its bidirectional relationship with the immune system, and its role in impacting health and disease, with emphasis on allergy, in early life. © 2014 Danone Nutricia Research. Pediatric Allergy and Immunology published by John Wiley & Sons Ltd.

Stepwise Organization of the β-Structure Identifies Key Regions Essential for the Propagation and Cytotoxicity of Insulin Amyloid Fibrils*

PubMed Central

Chatani, Eri; Imamura, Hiroshi; Yamamoto, Naoki; Kato, Minoru

2014-01-01

Amyloid fibrils are supramolecular assemblies, the deposition of which is associated with many serious diseases including Alzheimer, prion, and Huntington diseases. Several smaller aggregates such as oligomers and protofibrils have been proposed to play a role in early stages of the fibrillation process; however, little is known about how these species contribute to the formation of mature amyloid fibrils with a rigid cross-β structure. Here, we identified a new pathway for the formation of insulin amyloid fibrils at a high concentration of salt in which mature fibrils were formed in a stepwise manner via a prefibrillar intermediate: minute prefibrillar species initially accumulated, followed by the subsequent formation of thicker amyloid fibrils. Fourier transform infrared spectra suggested the sequential formation of two types of β-sheets with different strength hydrogen bonds, one of which was developed concomitantly with the mutual assembly of the prefibrillar intermediate to form mature fibrils. Interestingly, fibril propagation and cellular toxicity appeared only after the later step of structural organization, and a comparison of β-sheet regions between the prefibrillar intermediate and mature fibrils using proteolysis led to the proposal of specific regions essential for manifestation of these properties. PMID:24569992

Phagocytosis: Hungry, Hungry Cells.

PubMed

Gray, Matthew; Botelho, Roberto J

2017-01-01

Phagocytosis is the cellular internalization and sequestration of particulate matter into a `phagosome, which then matures into a phagolysosome. The phagolysosome then offers a specialized acidic and hydrolytic milieu that ultimately degrades the engulfed particle. In multicellular organisms, phagocytosis and phagosome maturation play two key physiological roles. First, phagocytic cells have an important function in tissue remodeling and homeostasis by eliminating apoptotic bodies, senescent cells and cell fragments. Second, phagocytosis is a critical weapon of the immune system, whereby cells like macrophages and neutrophils hunt and engulf a variety of pathogens and foreign particles. Not surprisingly, pathogens have evolved mechanisms to either block or alter phagocytosis and phagosome maturation, ultimately usurping the cellular machinery for their own survival. Here, we review past and recent discoveries that highlight how phagocytes recognize target particles, key signals that emanate after phagocyte-particle engagement, and how these signals help modulate actin-dependent remodeling of the plasma membrane that culminates in the release of the phagosome. We then explore processes related to early and late stages of phagosome maturation, which requires fusion with endosomes and lysosomes. We end this review by acknowledging that little is known about phagosome fission and even less is known about how phagosomes are resolved after particle digestion.

Development of immature stomata: evidence for epigenetic selection of a spacing pattern.

PubMed

Kagan, M L; Sachs, T

1991-07-01

In Sansevieria trifasciata as many as half the potential stomata remain immature. The development of all stomatal structures started at the same time and the early stages of the development of immature stomata had no special characteristics. Statistical analysis showed that the mature stomata were more evenly spaced than all potential stomata, both mature and immature. Furthermore, the distribution of mature stomata per unit area was more predictable or orderly than comparable structures of a random model that developed in the same way. These facts indicate that a nonrandom loss of many stomata by "immaturity" is a major determinant, acting during rather than preceding development, of the distribution of the mature, functional stomata. Thus in Sansevieria there is a selection of an epidermal pattern from an excess of cells that undergo the early stages of stomatal development.

Toxic effects and possible mechanisms of hydrogen sulfide and/or ammonia on porcine oocyte maturation in vitro.

PubMed

Yang, Lei-Lei; Zhao, Yong; Luo, Shi-Ming; Ma, Jun-Yu; Ge, Zhao-Jia; Shen, Wei; Yin, Shen

2018-03-15

Previous studies suggest that hydrogen sulfide (H 2 S) and ammonia (NH 3 ) are two major air pollutants which can cause damage to porcine health. However, the mechanisms underlying toxic effects of these compounds on porcine oocyte maturation are not clear. To clarify the mechanism, we evaluated the oocyte quality by detecting some events during oocytes maturation. In our study, porcine oocytes were cultured with different concentrations of Na 2 S and/or NH 4 Cl in vitro and the rate of the first polar body extrusion decreased significantly. Also, actin filament was seriously disrupted to damage the cytoskeleton which resulted in reduced rate of oocyte maturation. We explored the reactive oxygen species (ROS) generation and found that the ROS level was increased significantly after Na 2 S treatment but not after NH 4 Cl treatment. Moreover, early stage apoptosis rate was significantly increased and autophagy protein LC3 B expression level was higher in oocytes treated with Na 2 S and/or NH 4 Cl, which might be caused by ROS elevation. Additionally, exposure to Na 2 S and/or NH 4 Cl also caused ROS generation and early apoptosis in cumulus cells, which might further affect oocyte maturation in vitro. In summary, our data suggested that exposure to H 2 S and/or NH 3 decreased porcine oocyte maturation in vitro, which might be caused by actin disruption, ROS generation, early apoptosis and autophagy. Copyright © 2017 Elsevier B.V. All rights reserved.

Early puberty, negative peer influence, and problem behaviors in adolescent girls.

PubMed

Mrug, Sylvie; Elliott, Marc N; Davies, Susan; Tortolero, Susan R; Cuccaro, Paula; Schuster, Mark A

2014-01-01

To determine how early puberty and peer deviance relate to trajectories of aggressive and delinquent behavior in early adolescence and whether these relationships differ by race/ethnicity. In this longitudinal study, 2607 girls from 3 metropolitan areas and their parents were interviewed at ages 11, 13, and 16 years. Girls reported on their age of onset of menarche, best friend's deviant behavior, delinquency, and physical, relational, and nonphysical aggression. Parents provided information on family sociodemographic characteristics and girls' race/ethnicity. Sixteen percent of girls were classified as early maturers (defined by onset of menarche before age 11 years). Overall, relational and nonphysical aggression increased from age 11 to age 16, whereas delinquency and physical aggression remained stable. Early puberty was associated with elevated delinquency and physical aggression at age 11. The relationship with early puberty diminished over time for physical aggression but not for delinquency. Best friend's deviant behavior was linked with higher levels of all problem behaviors, but the effect lessened over time for most outcomes. Early puberty was associated with a stronger link between best friend's deviance and delinquency, suggesting increased vulnerability to negative peer influences among early-maturing girls. A similar vulnerability was observed for relational and nonphysical aggression among girls in the "other" racial/ethnic minority group only. Early puberty and friends' deviance may increase the risk of problem behavior in young adolescent girls. Although many of these associations dissipate over time, early-maturing girls are at risk of persistently higher delinquency and stronger negative peer influences.

Maturation and Collection of Yellow-Poplar Seeds in the Midsouth

Treesearch

F. T. Bonner

1976-01-01

Yellow-poplar fruits are best collected in late October when their color changes from green to yellow-green or yellow. There were no other obvious physical or chemical changes indicating maturity. The seeds are physiologically mature as early as September 1, although high fruit moisture contents make special handling necessary if fruits are collected at this time....

Mature Age Professionals: Factors Influencing Their Decision to Make a Career Change into Teaching

ERIC Educational Resources Information Center

Bauer, Carmel; Thomas, Sue; Sim, Cheryl

2017-01-01

This paper presents the early findings from a study that addresses the topic of mature age professionals making a career change into the secondary teaching profession by undertaking a postgraduate coursework initial teacher education program. The paper specifically addresses the factors that affect the decision for mature age professionals to make…

Experience-dependent development of spinal motor neurons

NASA Technical Reports Server (NTRS)

Inglis, F. M.; Zuckerman, K. E.; Kalb, R. G.; Walton, K. D. (Principal Investigator)

2000-01-01

Locomotor activity in many species undergoes pronounced alterations in early postnatal life, and environmental cues may be responsible for modifying this process. To determine how these events are reflected in the nervous system, we studied rats reared under two different conditions-the presence or absence of gravity-in which the performance of motor operations differed. We found a significant effect of rearing environment on the size and complexity of dendritic architecture of spinal motor neurons, particularly those that are likely to participate in postural control. These results provide evidence that neurons subserving motor function undergo activity-dependent maturation in early postnatal life in a manner analogous to sensory systems.

Working memory circuit as a function of increasing age in healthy adolescence: A systematic review and meta-analyses.

PubMed

Andre, Julia; Picchioni, Marco; Zhang, Ruibin; Toulopoulou, Timothea

2016-01-01

Working memory ability matures through puberty and early adulthood. Deficits in working memory are linked to the risk of onset of neurodevelopmental disorders such as schizophrenia, and there is a significant temporal overlap between the peak of first episode psychosis risk and working memory maturation. In order to characterize the normal working memory functional maturation process through this critical phase of cognitive development we conducted a systematic review and coordinate based meta-analyses of all the available primary functional magnetic resonance imaging studies (n = 382) that mapped WM function in healthy adolescents (10-17 years) and young adults (18-30 years). Activation Likelihood Estimation analyses across all WM tasks revealed increased activation with increasing subject age in the middle frontal gyrus (BA6) bilaterally, the left middle frontal gyrus (BA10), the left precuneus and left inferior parietal gyri (BA7; 40). Decreased activation with increasing age was found in the right superior frontal (BA8), left junction of postcentral and inferior parietal (BA3/40), and left limbic cingulate gyrus (BA31). These results suggest that brain activation during adolescence increased with age principally in higher order cortices, part of the core working memory network, while reductions were detected in more diffuse and potentially more immature neural networks. Understanding the process by which the brain and its cognitive functions mature through healthy adulthood may provide us with new clues to understanding the vulnerability to neurodevelopmental disorders.

Developmental changes in organization of structural brain networks.

PubMed

Khundrakpam, Budhachandra S; Reid, Andrew; Brauer, Jens; Carbonell, Felix; Lewis, John; Ameis, Stephanie; Karama, Sherif; Lee, Junki; Chen, Zhang; Das, Samir; Evans, Alan C

2013-09-01

Recent findings from developmental neuroimaging studies suggest that the enhancement of cognitive processes during development may be the result of a fine-tuning of the structural and functional organization of brain with maturation. However, the details regarding the developmental trajectory of large-scale structural brain networks are not yet understood. Here, we used graph theory to examine developmental changes in the organization of structural brain networks in 203 normally growing children and adolescents. Structural brain networks were constructed using interregional correlations in cortical thickness for 4 age groups (early childhood: 4.8-8.4 year; late childhood: 8.5-11.3 year; early adolescence: 11.4-14.7 year; late adolescence: 14.8-18.3 year). Late childhood showed prominent changes in topological properties, specifically a significant reduction in local efficiency, modularity, and increased global efficiency, suggesting a shift of topological organization toward a more random configuration. An increase in number and span of distribution of connector hubs was found in this age group. Finally, inter-regional connectivity analysis and graph-theoretic measures indicated early maturation of primary sensorimotor regions and protracted development of higher order association and paralimbic regions. Our finding reveals a time window of plasticity occurring during late childhood which may accommodate crucial changes during puberty and the new developmental tasks that an adolescent faces.

Preclinical Immunomodulation by the Probiotic Bifidobacterium breve M-16V in Early Life.

PubMed

Rigo-Adrover, Maria Del Mar; Franch, Àngels; Castell, Margarida; Pérez-Cano, Francisco José

2016-01-01

This study aimed to investigate the effect of supplementation with the probiotic Bifidobacterium breve M-16V on the maturation of the intestinal and circulating immune system during suckling. In order to achieve this purpose, neonatal Lewis rats were supplemented with the probiotic strain from the 6th to the 18th day of life. The animals were weighed during the study, and faecal samples were obtained and evaluated daily. On day 19, rats were euthanized and intestinal wash samples, mesenteric lymph node (MLN) cells, splenocytes and intraepithelial lymphocytes (IEL) were obtained. The probiotic supplementation in early life did not modify the growth curve and did not enhance the systemic immune maturation. However, it increased the proportion of cells bearing TLR4 in the MLN and IEL, and enhanced the percentage of the integrin αEβ7+ and CD62L+ cells in the MLN and that of the integrin αEβ7+ cells in the IEL, suggesting an enhancement of the homing process of naïve T lymphocytes to the MLN, and the retention of activated lymphocytes in the intraepithelial compartment. Interestingly, B. breve M-16V enhanced the intestinal IgA synthesis. In conclusion, supplementation with the probiotic strain B. breve M-16V during suckling improves the development of mucosal immunity in early life.

The Economy of the Totalitarian Mind: the Case of the Immigrant Child.

PubMed

Kelley-Lainé, Kathleen

2016-12-01

Immigration in early childhood can be considered as a traumatic situation. It often goes unrecognized since children adapt to most conditions and conform to their environment with astonishing agility. Inspired by the sensitive work of Sándor Ferenczi, and Donald Winnicott, regarding the psychic economy of maturational processes, the author explores the concept of totalitarian functioning and its obstruction of the growing psyche. Before birth we are all totalitarian, one with the mother; this symbiotic, invincible state of survival mode is prolonged as the immature newborn child ignores the requirements of reality and enjoys omnipotent pleasure through hallucination. The loss of place in immigration often becomes the loss of identity-the question of "where am I?" becomes confused with "who am I?". Clinical practice exposes this fragility in adults torn from their home environment at an early age, forced into precocious maturity, never to grow up in reality. Through clinical examples, the author illustrates how totalitarian mental functioning of "all or nothing, right or wrong, black or white" is exposed in the transference and can be worked through within the psychoanalytical space.

The microprocessor component, DGCR8, is essential for early B-cell development in mice.

PubMed

Brandl, Andreas; Daum, Patrick; Brenner, Sven; Schulz, Sebastian R; Yap, Desmond Yat-Hin; Bösl, Michael R; Wittmann, Jürgen; Schuh, Wolfgang; Jäck, Hans-Martin

2016-12-01

microRNAs (miRNAs) are important posttranscriptional regulators during hematopoietic lineage commitment and lymphocyte development. Mature miRNAs are processed from primary miRNA transcripts in two steps by the microprocessor complex, consisting of Drosha and its partner DiGeorge Critical Region 8 (DGCR8), and the RNAse III enzyme, Dicer. Conditional ablations of Drosha and Dicer have established the importance of both RNAses in B- and T-cell development. Here, we show that a cre-mediated B-cell specific deletion of DGCR8 in mice results in a nearly complete maturation block at the transition from the pro-B to the pre-B cell stage, and a failure to upregulate Ig μ heavy chain expression in pro-B cells. Furthermore, we found that the death of freshly isolated DGCR8-deficient pro-B cells could be partially prevented by enforced Bcl2 expression. We conclude from these findings that the microprocessor component DGCR8 is essential for survival and differentiation of early B-cell progenitors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Lys-Asp-Tyr Triad within the Mite Allergen Der p 1 Propeptide Is a Critical Structural Element for the pH-Dependent Initiation of the Protease Maturation.

PubMed

Chevigné, Andy; Campizi, Vincenzo; Szpakowska, Martyna; Bourry, David; Dumez, Marie-Eve; Martins, José C; Matagne, André; Galleni, Moreno; Jacquet, Alain

2017-05-20

The major house dust mite allergen, Der p 1, is a papain-like cysteine protease expressed as an inactive precursor, proDer p 1, carrying an N-terminal propeptide with a unique structure. The maturation of the zymogen into an enzymatically-active form of Der p 1 is a multistep autocatalytic process initiated under acidic conditions through conformational changes of the propeptide, leading to the loss of its inhibitory ability and its subsequent gradual cleavage. The aims of this study were to characterize the residues present in the Der p 1 propeptide involved in the initiation of the zymogen maturation process, but also to assess the impact of acidic pH on the propeptide structure, the activity of Der p 1 and the fate of the propeptide. Using various complementary enzymatic and structural approaches, we demonstrated that a structural triad K17p-D51p-Y19p within the N-terminal domain of the propeptide is essential for its stabilization and the sensing of pH changes. Particularly, the protonation of D51p under acidic conditions unfolds the propeptide through disruption of the K17p-D51p salt bridge, reduces its inhibition capacity and unmasks the buried residues K17p and Y19p constituting the first maturation cleavage site of the zymogen. Our results also evidenced that this triad acts in a cooperative manner with other propeptide pH-responsive elements, including residues E56p and E80p, to promote the propeptide unfolding and/or to facilitate its proteolysis. Furthermore, we showed that acidic conditions modify Der p 1 proteolytic specificity and confirmed that the formation of the first intermediate represents the limiting step of the in vitro Der p 1 maturation process. Altogether, our results provide new insights into the early events of the mechanism of proDer p 1 maturation and identify a unique structural triad acting as a stabilizing and a pH-sensing regulatory element.

Alpha-fetoprotein, stem cells and cancer: how study of the production of alpha-fetoprotein during chemical hepatocarcinogenesis led to reaffirmation of the stem cell theory of cancer.

PubMed

Sell, Stewart

2008-01-01

Identification of the cells in the liver that produce alpha-fetoprotein during development, in response to liver injury and during the early stages of chemical hepatocarcinogenesis led to the conclusion that maturation arrest of liver-determined tissue stem cells was the cellular process that gives rise to hepatocellular carcinomas. When the cellular changes in these processes were compared to that of the formation of teratocarcinomas, the hypothesis arose that all cancers arise from maturation arrest of tissue-determined stem cells. This was essentially a reinterpretation of the embryonal rest theory of cancer whereby tissue stem cells take the role of embryonal rests. A corollary of the stem cell theory of the origin of cancer is that cancers contain the same functional cell populations as normal tissues: stem cells, transit-amplifying cells and mature cells. Cancer stem cells retain the essential feature of normal stem cells: the ability to self-renew. Growth of cancers is due to continued proliferation of cancer transit-amplifying cells that do not differentiate to mature cells (maturation arrest). On the other hand, cancer stem cells generally divide very rarely and contribute little to tumor growth. However, the presence of cancer stem cells in tumors is believed to be responsible for the properties of immortalization, transplantability and resistance to therapy characteristic of cancers. Current therapies for cancer (chemotherapy, radiotherapy, antiangiogenesis and differentiation therapy) are directed against the cancer transit-amplifying cells. When these therapies are discontinued, the cancer reforms from the cancer stem cells. Therapy directed toward interruption of the cell signaling pathways that maintain cancer stem cells could lead to new modalities to the prevention of regrowth of the cancer. Copyright 2008 S. Karger AG, Basel.

ALPHA-FETOPROTEIN (AFP), STEM CELLS, AND CANCER: HOW STUDY OF THE PRODUCTION OF AFP DURING CHEMICAL HEPATOCARCINOGENESIS LED TO REAFFIRMATION OF THE STEM CELL THEORY OF CANCER

PubMed Central

Sell, Stewart

2008-01-01

Identification of the cells in the liver that produce alpha-fetoprotein (AFP) during development, in response to liver injury, and during the early stages of chemical hepatocarcinogenesis led to the conclusion that maturation arrest of liver-determined tissue stem cells was the cellular process that gives rise to hepatocellular carcinomas (HCC). When the cellular changes in these processes were compared that of the formation of teratocarcinomas, the hypothesis arose that all cancers arise from maturation arrest of tissue determined stem cells. This was essentially a reinterpretation of the embryonal rest theory of cancer whereby tissue stem cells take the role of embryonal rests. A corollary of the stem cell theory of the origin of cancer is that cancers contain the same functional cell populations as do normal tissues: stem cells, transit-amplifying cells, and mature cells. Cancer stem cells retain the essential feature of normal stem cells: the ability to self-renew. Growth of cancers is due to continued proliferation of cancer transit-amplifying cells that do not differentiate to mature cells (maturation arrest). On the other hand, cancer stem cells generally divide very rarely and contribute little to tumor growth. However, the presence of cancer stem cells in tumors is believed to be responsible for the properties of immortalization, transplantability and resistance to therapy characteristic of cancers. Current therapies for cancer (chemotherapy, radiotherapy, anti-angiogenesis and differentiation therapy) are directed against the cancer transit amplifying cells. When these therapies are discontinued, the cancer re-forms from the cancer stem cells. Therapy directed toward interruption of the cell-signaling pathways that maintain cancer stem cells could lead to new modalities to the prevention of re-growth of the cancer. PMID:18612221

Zcchc11 Uridylates Mature miRNAs to Enhance Neonatal IGF-1 Expression, Growth, and Survival

PubMed Central

Kozlowski, Elyse; Matsuura, Kori Y.; Ferrari, Joseph D.; Morris, Samantha A.; Powers, John T.; Daley, George Q.; Quinton, Lee J.; Mizgerd, Joseph P.

2012-01-01

The Zcchc11 enzyme is implicated in microRNA (miRNA) regulation. It can uridylate let-7 precursors to decrease quantities of the mature miRNA in embryonic stem cell lines, suggested to mediate stem cell maintenance. It can uridylate mature miR-26 to relieve silencing activity without impacting miRNA content in cancer cell lines, suggested to mediate cytokine and growth factor expression. Broader roles of Zcchc11 in shaping or remodeling the miRNome or in directing biological or physiological processes remain entirely speculative. We generated Zcchc11-deficient mice to address these knowledge gaps. Zcchc11 deficiency had no impact on embryogenesis or fetal development, but it significantly decreased survival and growth immediately following birth, indicating a role for this enzyme in early postnatal fitness. Deep sequencing of small RNAs from neonatal livers revealed roles of this enzyme in miRNA sequence diversity. Zcchc11 deficiency diminished the lengths and terminal uridine frequencies for diverse mature miRNAs, but it had no influence on the quantities of any miRNAs. The expression of IGF-1, a liver-derived protein essential to early growth and survival, was enhanced by Zcchc11 expression in vitro, and miRNA silencing of IGF-1 was alleviated by uridylation events observed to be Zcchc11-dependent in the neonatal liver. In neonatal mice, Zcchc11 deficiency significantly decreased IGF-1 mRNA in the liver and IGF-1 protein in the blood. We conclude that the Zcchc11-mediated terminal uridylation of mature miRNAs is pervasive and physiologically significant, especially important in the neonatal period for fostering IGF-1 expression and enhancing postnatal growth and survival. We propose that the miRNA 3′ terminus is a regulatory node upon which multiple enzymes converge to direct silencing activity and tune gene expression. PMID:23209448

Dynamic distribution and the role of abscisic acid during seed development of a lady’s slipper orchid, Cypripedium formosanum

PubMed Central

Lee, Yung-I; Chung, Mei-Chu; Yeung, Edward C.; Lee, Nean

2015-01-01

Background and Aims Although abscisic acid (ABA) is commonly recognized as a primary cause of seed dormancy, there is a lack of information on the role of ABA during orchid seed development. In order to address this issue, the localization and quantification of ABA were determined in developing seeds of Cypripedium formosanum. Methods The endogenous ABA profile of seeds was measured by enzyme-linked immunosorbent assay (ELISA). Temporal and spatial distributions of ABA in developing seeds were visualized by immunohistochemical staining with monoclonal ABA antibodies. Fluoridone was applied to test the causal relationship between ABA content and seed germinability. Key Results ABA content was low at the proembryo stage, then increased rapidly from 120 to 150 days after pollination (DAP), accompanied by a progressive decrease in water content and seed germination. Immunofluorescence signals indicated an increase in fluorescence over time from the proembryo stage to seed maturation. From immunogold labelling, gold particles could be seen within the cytoplasm of embryo-proper cells during the early stages of seed development. As seeds approached maturity, increased localization of gold particles was observed in the periplasmic space, the plasmalemma between embryo-proper cells, the surface wall of the embryo proper, and the inner walls of inner seed-coat cells. At maturity, gold particles were found mainly in the apoplast, such as the surface wall of the embryo proper, and the shrivelled inner and outer seed coats. Injection of fluoridone into capsules resulted in enhanced germination of mature seeds. Conclusions The results indicate that ABA is the key inhibitor of germination in C. formosanum. The distinct accumulation pattern of ABA suggests that it is synthesized in the cytosol of embryo cells during the early stages of seed development, and then exported to the apoplastic region of the cells for subsequent regulatory processes as seeds approach maturity. PMID:26105185

microRNA in Human Reproduction.

PubMed

Eisenberg, Iris; Kotaja, Noora; Goldman-Wohl, Debra; Imbar, Tal

2015-01-01

microRNAs constitute a large family of approximately 21-nucleotide-long, noncoding RNAs. They emerged more than 20 years ago as key posttranscriptional regulators of gene expression. The regulatory role of these small RNA molecules has recently begun to be explored in the human reproductive system. microRNAs have been shown to play an important role in control of reproductive functions, especially in the processes of oocyte maturation, folliculogenesis, corpus luteum function, implantation, and early embryonic development. Knockout of Dicer, the cytoplasmic enzyme that cleaves the pre-miRNA to its mature form, results in postimplantation embryonic lethality in several animal models, attributing to these small RNA vital functions in reproduction and development. Another intriguing characteristic of microRNAs is their presence in body fluids in a remarkably stable form that is protected from endogenous RNase activity. In this chapter we will describe the current knowledge on microRNAs, specifically relating to human gonadal cells. We will focus on their role in the ovarian physiologic process and ovulation dysfunction, regulation of spermatogenesis and male fertility, and putative involvement in human normal and aberrant trophoblast differentiation and invasion through the process of placentation.

Age-related changes in spatiotemporal characteristics of gait accompany ongoing lower limb linear growth in late childhood and early adolescence.

PubMed

Froehle, Andrew W; Nahhas, Ramzi W; Sherwood, Richard J; Duren, Dana L

2013-05-01

Walking gait is generally held to reach maturity, including walking at adult-like velocities, by 7-8 years of age. Lower limb length, however, is a major determinant of gait, and continues to increase until 13-15 years of age. This study used a sample from the Fels Longitudinal Study (ages 8-30 years) to test the hypothesis that walking with adult-like velocity on immature lower limbs results in the retention of immature gait characteristics during late childhood and early adolescence. There was no relationship between walking velocity and age in this sample, whereas the lower limb continued to grow, reaching maturity at 13.2 years in females and 15.6 years in males. Piecewise linear mixed models regression analysis revealed significant age-related trends in normalized cadence, initial double support time, single support time, base of support, and normalized step length in both sexes. Each trend reached its own, variable-specific age at maturity, after which the gait variables' relationships with age reached plateaus and did not differ significantly from zero. Offsets in ages at maturity occurred among the gait variables, and between the gait variables and lower limb length. The sexes also differed in their patterns of maturation. Generally, however, immature walkers of both sexes took more frequent and relatively longer steps than did mature walkers. These results support the hypothesis that maturational changes in gait accompany ongoing lower limb growth, with implications for diagnosing, preventing, and treating movement-related disorders and injuries during late childhood and early adolescence. Copyright © 2012 Elsevier B.V. All rights reserved.

Proteomics Coupled with Metabolite and Cell Wall Profiling Reveal Metabolic Processes of a Developing Rice Stem Internode

PubMed Central

Lin, Fan; Williams, Brad J.; Thangella, Padmavathi A. V.; Ladak, Adam; Schepmoes, Athena A.; Olivos, Hernando J.; Zhao, Kangmei; Callister, Stephen J.; Bartley, Laura E.

2017-01-01

Internodes of grass stems function in mechanical support, transport, and, in some species, are a major sink organ for carbon in the form of cell wall polymers. This study reports cell wall composition, proteomic, and metabolite analyses of the rice elongating internode. Cellulose, lignin, and xylose increase as a percentage of cell wall material along eight segments of the second rice internode (internode II) at booting stage, from the younger to the older internode segments, indicating active cell wall synthesis. Liquid-chromatography tandem mass spectrometry (LC-MS/MS) of trypsin-digested proteins from this internode at booting reveals 2,547 proteins with at least two unique peptides in two biological replicates. The dataset includes many glycosyltransferases, acyltransferases, glycosyl hydrolases, cell wall-localized proteins, and protein kinases that have or may have functions in cell wall biosynthesis or remodeling. Phospho-enrichment of internode II peptides identified 21 unique phosphopeptides belonging to 20 phosphoproteins including a leucine rich repeat-III family receptor like kinase. GO over-representation and KEGG pathway analyses highlight the abundances of proteins involved in biosynthetic processes, especially the synthesis of secondary metabolites such as phenylpropanoids and flavonoids. LC-MS/MS of hot methanol-extracted secondary metabolites from internode II at four stages (booting/elongation, early mature, mature, and post mature) indicates that internode secondary metabolites are distinct from those of roots and leaves, and differ across stem maturation. This work fills a void of in-depth proteomics and metabolomics data for grass stems, specifically for rice, and provides baseline knowledge for more detailed studies of cell wall synthesis and other biological processes characteristic of internode development, toward improving grass agronomic properties. PMID:28751896

Proteomics Coupled with Metabolite and Cell Wall Profiling Reveal Metabolic Processes of a Developing Rice Stem Internode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Fan; Williams, Brad J.; Thangella, Padmavathi A. V.

Internodes of grass stems function in mechanical support, transport, and, in some species, are a major sink organ for carbon in the form of cell wall polymers. This study reports cell wall composition, proteomic and metabolite analyses of the rice elongating internode. Along eight segments of the second rice internode (internode II) at booting stage, cellulose, lignin, and xylose increase as a percentage of cell wall material from the younger to the older internode segments, indicating active cell wall synthesis. Liquid-chromatography tandem mass spectrometry (LC-MS/MS) of trypsin-digested peptides of size-fractionated proteins extracted from this internode at booting reveals 2547proteins withmore » at least two unique peptides. The dataset includes many glycosyltransferases, acyltransferases, glycosyl hydrolases, cell wall-localized proteins, and protein kinases that have or may have functions in cell wall biosynthesis or remodeling. Phospho-enrichment of the internode II peptides identified 21 unique phosphopeptides belonging to 20 phosphoproteins including an LRR-III family receptor like kinase. GO over-representation and KEGG pathway analyses highlight the abundances of internode proteins involved in biosynthetic processes, especially the synthesis of secondary metabolites such as phenylpropanoids and flavonoids. LC-MS of hot methanol-extracted secondary metabolites from internode II at four stages (elongation, early mature, mature and post mature) indicates that secondary metabolites in stems are distinct from those of roots and leaves, and differ during stem maturation. This work fills a void of knowledge of proteomics and metabolomics data for grass stems, specifically for rice, and provides baseline knowledge for more detailed studies of cell wall synthesis and other biological processes during internode development, toward improving grass agronomic properties.« less

Evolution and the Growth Process: Natural Selection of Entrepreneurial Traits.

PubMed

Galor, Oded; Michalopoulos, Stelios

2012-03-01

This research suggests that a Darwinian evolution of entrepreneurial spirit played a significant role in the process of economic development and the dynamics of inequality within and across societies. The study argues that entrepreneurial spirit evolved non-monotonically in the course of human history. In early stages of development, risk-tolerant, growth promoting traits generated an evolutionary advantage and their increased representation accelerated the pace of technological progress and the process of economic development. In mature stages of development, however, risk-averse traits gained an evolutionary advantage, diminishing the growth potential of advanced economies and contributing to convergence in economic growth across countries.

Evolution and the Growth Process: Natural Selection of Entrepreneurial Traits*

PubMed Central

Galor, Oded; Michalopoulos, Stelios

2013-01-01

This research suggests that a Darwinian evolution of entrepreneurial spirit played a significant role in the process of economic development and the dynamics of inequality within and across societies. The study argues that entrepreneurial spirit evolved non-monotonically in the course of human history. In early stages of development, risk-tolerant, growth promoting traits generated an evolutionary advantage and their increased representation accelerated the pace of technological progress and the process of economic development. In mature stages of development, however, risk-averse traits gained an evolutionary advantage, diminishing the growth potential of advanced economies and contributing to convergence in economic growth across countries. PMID:25089059

Health-related quality of life of Portuguese children and adolescents according to their biological maturation and volume of physical activity.

PubMed

Garcia, Catarina; Teles, Júlia; Barrigas, Carlos; Fragoso, Isabel

2018-06-01

The purpose of this study was to analyze the relationship between biological maturation and health-related quality of life (HRQoL) in Portuguese children and adolescents of both sexes when the effect of chronological age (CA) and volume of physical activity (VPA) were removed. HRQoL, biological maturation, CA, and VPA were assessed in 750 children and adolescents, 11-17 years old, from 3 schools in Lisbon, Portugal. The KIDSCREEN-52 was used to assess HRQoL. Maturity indicator was bone age (BA), using Tanner-Whitehouse III method (TW3). The participants were classified into three different maturity categories: late, on time, and early maturers. VPA was assessed by questionnaire (RAPIL II). An analysis of covariance (ANCOVA), using the CA and the VPA as covariates was completed. The level of significance was set at p ≤ 0.05. Analysis of covariance suggested an influence of biological maturation in physical well-being dimension in both sexes, with early-maturing girls and boys having worst perception. Maturity groups were also influent in moods and emotions for girls. CA seems to be particularly important in self-perception and parent relation and home life for girls and in school environment for boys. Biological maturation and CA have relevant impact on some HRQoL dimensions. These variables, due to their nature and effect should be considered particularly when working with specific domains of HRQoL as physical well-being in both sexes, moods and emotions and self-perception and parent relation and home life for girls and in school environment for boys.

Expression of Putative Immune Response Genes during Early Ontogeny in the Coral Acropora millepora

PubMed Central

Puill-Stephan, Eneour; Seneca, François O.; Miller, David J.; van Oppen, Madeleine J. H.; Willis, Bette L.

2012-01-01

Background Corals, like many other marine invertebrates, lack a mature allorecognition system in early life history stages. Indeed, in early ontogeny, when corals acquire and establish associations with various surface microbiota and dinoflagellate endosymbionts, they do not efficiently distinguish between closely and distantly related individuals from the same population. However, very little is known about the molecular components that underpin allorecognition and immunity responses or how they change through early ontogeny in corals. Methodology/Principal Findings Patterns in the expression of four putative immune response genes (apextrin, complement C3, and two CELIII type lectin genes) were examined in juvenile colonies of Acropora millepora throughout a six-month post-settlement period using quantitative real-time PCR (qPCR). Expression of a CELIII type lectin gene peaked in the fourth month for most of the coral juveniles sampled and was significantly higher at this time than at any other sampling time during the six months following settlement. The timing of this increase in expression levels of putative immune response genes may be linked to allorecognition maturation which occurs around this time in A.millepora. Alternatively, the increase may represent a response to immune challenges, such as would be involved in the recognition of symbionts (such as Symbiodinium spp. or bacteria) during winnowing processes as symbioses are fine-tuned. Conclusions/Significance Our data, although preliminary, are consistent with the hypothesis that lectins may play an important role in the maturation of allorecognition responses in corals. The co-expression of lectins with apextrin during development of coral juveniles also raises the possibility that these proteins, which are components of innate immunity in other invertebrates, may influence the innate immune systems of corals through a common pathway or system. However, further studies investigating the expression of these genes in alloimmune-challenged corals are needed to further clarify emerging evidence of a complex innate immunity system in corals. PMID:22792163

Expression of putative immune response genes during early ontogeny in the coral Acropora millepora.

PubMed

Puill-Stephan, Eneour; Seneca, François O; Miller, David J; van Oppen, Madeleine J H; Willis, Bette L

2012-01-01

Corals, like many other marine invertebrates, lack a mature allorecognition system in early life history stages. Indeed, in early ontogeny, when corals acquire and establish associations with various surface microbiota and dinoflagellate endosymbionts, they do not efficiently distinguish between closely and distantly related individuals from the same population. However, very little is known about the molecular components that underpin allorecognition and immunity responses or how they change through early ontogeny in corals. Patterns in the expression of four putative immune response genes (apextrin, complement C3, and two CELIII type lectin genes) were examined in juvenile colonies of Acropora millepora throughout a six-month post-settlement period using quantitative real-time PCR (qPCR). Expression of a CELIII type lectin gene peaked in the fourth month for most of the coral juveniles sampled and was significantly higher at this time than at any other sampling time during the six months following settlement. The timing of this increase in expression levels of putative immune response genes may be linked to allorecognition maturation which occurs around this time in A. millepora. Alternatively, the increase may represent a response to immune challenges, such as would be involved in the recognition of symbionts (such as Symbiodinium spp. or bacteria) during winnowing processes as symbioses are fine-tuned. Our data, although preliminary, are consistent with the hypothesis that lectins may play an important role in the maturation of allorecognition responses in corals. The co-expression of lectins with apextrin during development of coral juveniles also raises the possibility that these proteins, which are components of innate immunity in other invertebrates, may influence the innate immune systems of corals through a common pathway or system. However, further studies investigating the expression of these genes in alloimmune-challenged corals are needed to further clarify emerging evidence of a complex innate immunity system in corals.

Fluency variation in adolescents.

PubMed

Furquim de Andrade, Claudia Regina; de Oliveira Martins, Vanessa

2007-10-01

The Speech Fluency Profile of fluent adolescent speakers of Brazilian Portuguese, were examined with respect to gender and neurolinguistic variations. Speech samples of 130 male and female adolescents, aged between 12;0 and 17;11 years were gathered. They were analysed according to type of speech disruption; speech rate; and frequency of speech disruptions. Statistical analysis did not find significant differences between genders for the variables studied. However, regarding the phases of adolescence (early: 12;0-14;11 years; late: 15;0-17;11 years), statistical differences were observed for all of the variables. As for neurolinguistic maturation, a decrease in the number of speech disruptions and an increase in speech rate occurred during the final phase of adolescence, indicating that the maturation of the motor and linguistic processes exerted an influence over the fluency profile of speech.

Effects of maturity and harvest season of grass-clover silage and of forage-to-concentrate ratio on milk production of dairy cows.

PubMed

Alstrup, L; Søegaard, K; Weisbjerg, M R

2016-01-01

This study examined the effects of maturity and season of harvest of grass-clover silages and forage:concentrate ratio (FCR) on feed intake, milk production, chewing activity, digestibility, and fecal consistency of Holstein dairy cows. Comparison included 2 cuts in spring season (early and late) and 2 cuts in summer season (early and late) combined with high FCR (80:20; HFCR) and low FCR (50:50; LFCR). The experiment included 24 lactating Holstein cows arranged as 2 repeated 4 × 4 Latin squares with four 21-d periods and included measurements of feed composition, feed intake, milk production and composition, chewing activities, digestibilities, and fecal dry matter (DM) concentration and scoring. Forages were fed as two-thirds grass-clover and one-third corn silage supplemented with either 20 or 50% concentrate. Rations were fed ad libitum as total mixed rations. Early maturity cuts were more digestible than late maturity cuts, which was also reflected in a lower concentration of neutral detergent fiber (NDF) in early maturity cuts, whereas summer cuts had a higher crude protein concentration than spring cuts. Increased maturity decreased the intake of DM and energy, increased NDF intake, and decreased the yield of energy-corrected milk (ECM). Summer cuts increased the ECM yield compared with spring cuts. Milk yield (kg and kilogram of ECM) was numerically higher for cows fed early summer cut, independent of FCR in the ration. Milk protein concentration decreased, or tended to decrease, with maturity. For LFCR, the milk fat concentration increased with maturity resulting in a decreased protein:fat ratio. At HFCR, increased maturity increased the time spent chewing per kilogram of DM. Digestibility of silages was positively correlated with the fecal DM concentration. The DM intake and ECM yield showed no significant response to FCR in the ration, but the milk composition was affected. The LFCR decreased the milk fat percentage and increased the milk protein percentage numerically followed by a higher protein:fat ratio. Total chewing time per kilogram of DM decreased and total chewing time per kilogram of NDF increased with LFCR. This study indicates that silages from summer cuts have a similar value for milk production as do spring cuts, when forage digestibility is taken into account. Moreover, it appears that supplementation of extra concentrate has no effect on ECM production when forages with a high digestibility are fed, and that the physical structural value is adequate even when feeding high digestible forages. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effects of endocrine-disrupting contaminants on amphibian oogenesis: methoxychlor inhibits progesterone-induced maturation of Xenopus laevis oocytes in vitro.

PubMed Central

Pickford, D B; Morris, I D

1999-01-01

There is currently little evidence of pollution-induced endocrine dysfunction in amphibia, in spite of widespread concern over global declines in this ecologically diverse group. Data regarding the potential effects of endocrine-disrupting contaminants (EDCs) on reproductive function in amphibia are particularly lacking. We hypothesized that estrogenic EDCs may disrupt progesterone-induced oocyte maturation in the adult amphibian ovary, and tested this with an in vitro germinal vesicle breakdown assay using defolliculated oocytes from the African clawed frog, Xenopus laevis. While a variety of natural and synthetic estrogens and xenoestrogens were inactive in this system, the proestrogenic pesticide methoxychlor was a surprisingly potent inhibitor of progesterone-induced oocyte maturation (median inhibitive concentration, 72 nM). This inhibitory activity was specific to methoxychlor, rather than to its estrogenic contaminants or metabolites, and was not antagonized by the estrogen receptor antagonist ICI 182,780, suggesting that this activity is not estrogenic per se. The inhibitory activity of methoxychlor was dose dependent, reversible, and early acting. However, washout was unable to reverse the effect of short methoxychlor exposure, and methoxychlor did not competitively displace [3H]progesterone from a specific binding site in the oocyte plasma membrane. Therefore, methoxychlor may exert its action not directly at the site of progesterone action, but downstream on early events in maturational signaling, although the precise mechanism of action is unclear. The activity of methoxychlor in this system indicates that xenobiotics may exert endocrine-disrupting effects through interference with progestin-regulated processes and through mechanisms other than receptor antagonism. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:10090707

The early mature part of bacterial twin-arginine translocation (Tat) precursor proteins contributes to TatBC receptor binding.

PubMed

Ulfig, Agnes; Freudl, Roland

2018-05-11

The twin-arginine translocation (Tat) pathway transports folded proteins across bacterial membranes. Tat precursor proteins possess a conserved twin-arginine (RR) motif in their signal peptides that is involved in the binding of the proteins to the membrane-associated TatBC receptor complex. In addition, the hydrophobic region in the Tat signal peptides also contributes to TatBC binding, but whether regions beyond the signal-peptide cleavage site are involved in this process is unknown. Here, we analyzed the contribution of the early mature protein part of the Escherichia coli trimethylamine N -oxide reductase (TorA) to productive TatBC receptor binding. We identified substitutions in the 30 amino acids immediately following the TorA signal peptide (30aa-region) that restored export of a transport-defective TorA[KQ]-30aa-MalE precursor, in which the RR residues had been replaced by a lysine-glutamine pair. Some of these substitutions increased the hydrophobicity of the N-terminal part of the 30aa-region and thereby likely enhanced hydrophobic substrate-receptor interactions within the hydrophobic TatBC substrate-binding cavity. Another class of substitutions increased the positive net charge of the region's C-terminal part, presumably leading to strengthened electrostatic interactions between the mature substrate part and the cytoplasmic TatBC regions. Furthermore, we identified substitutions in the C-terminal domains of TatB following the transmembrane segment that restored transport of various transport-defective TorA-MalE derivatives. Some of these substitutions most likely affected the orientation or conformation of the flexible, carboxy-proximal helices of TatB. Therefore, we propose that a tight accommodation of the folded mature region by TatB contributes to productive binding of Tat substrates to TatBC. © 2018 Ulfig and Freudl.

High Content Analysis of Hippocampal Neuron-Astrocyte Co-cultures Shows a Positive Effect of Fortasyn Connect on Neuronal Survival and Postsynaptic Maturation.

PubMed

van Deijk, Anne-Lieke F; Broersen, Laus M; Verkuyl, J Martin; Smit, August B; Verheijen, Mark H G

2017-01-01

Neuronal and synaptic membranes are composed of a phospholipid bilayer. Supplementation with dietary precursors for phospholipid synthesis -docosahexaenoic acid (DHA), uridine and choline- has been shown to increase neurite outgrowth and synaptogenesis both in vivo and in vitro . A role for multi-nutrient intervention with specific precursors and cofactors has recently emerged in early Alzheimer's disease, which is characterized by decreased synapse numbers in the hippocampus. Moreover, the medical food Souvenaid, containing the specific nutrient combination Fortasyn Connect (FC), improves memory performance in early Alzheimer's disease patients, possibly via maintaining brain connectivity. This suggests an effect of FC on synapses, but the underlying cellular mechanism is not fully understood. Therefore, we investigated the effect of FC (consisting of DHA, eicosapentaenoic acid (EPA), uridine, choline, phospholipids, folic acid, vitamins B12, B6, C and E, and selenium), on synaptogenesis by supplementing it to primary neuron-astrocyte co-cultures, a cellular model that mimics metabolic dependencies in the brain. We measured neuronal developmental processes using high content screening in an automated manner, including neuronal survival, neurite morphology, as well as the formation and maturation of synapses. Here, we show that FC supplementation resulted in increased numbers of neurons without affecting astrocyte number. Furthermore, FC increased postsynaptic PSD95 levels in both immature and mature synapses. These findings suggest that supplementation with FC to neuron-astrocyte co-cultures increased both neuronal survival and the maturation of postsynaptic terminals, which might aid the functional interpretation of FC-based intervention strategies in neurological diseases characterized by neuronal loss and impaired synaptic functioning.

High Content Analysis of Hippocampal Neuron-Astrocyte Co-cultures Shows a Positive Effect of Fortasyn Connect on Neuronal Survival and Postsynaptic Maturation

PubMed Central

van Deijk, Anne-Lieke F.; Broersen, Laus M.; Verkuyl, J. Martin; Smit, August B.; Verheijen, Mark H. G.

2017-01-01

Neuronal and synaptic membranes are composed of a phospholipid bilayer. Supplementation with dietary precursors for phospholipid synthesis –docosahexaenoic acid (DHA), uridine and choline– has been shown to increase neurite outgrowth and synaptogenesis both in vivo and in vitro. A role for multi-nutrient intervention with specific precursors and cofactors has recently emerged in early Alzheimer's disease, which is characterized by decreased synapse numbers in the hippocampus. Moreover, the medical food Souvenaid, containing the specific nutrient combination Fortasyn Connect (FC), improves memory performance in early Alzheimer's disease patients, possibly via maintaining brain connectivity. This suggests an effect of FC on synapses, but the underlying cellular mechanism is not fully understood. Therefore, we investigated the effect of FC (consisting of DHA, eicosapentaenoic acid (EPA), uridine, choline, phospholipids, folic acid, vitamins B12, B6, C and E, and selenium), on synaptogenesis by supplementing it to primary neuron-astrocyte co-cultures, a cellular model that mimics metabolic dependencies in the brain. We measured neuronal developmental processes using high content screening in an automated manner, including neuronal survival, neurite morphology, as well as the formation and maturation of synapses. Here, we show that FC supplementation resulted in increased numbers of neurons without affecting astrocyte number. Furthermore, FC increased postsynaptic PSD95 levels in both immature and mature synapses. These findings suggest that supplementation with FC to neuron-astrocyte co-cultures increased both neuronal survival and the maturation of postsynaptic terminals, which might aid the functional interpretation of FC-based intervention strategies in neurological diseases characterized by neuronal loss and impaired synaptic functioning. PMID:28824363

Elucidating the mechanisms linking early pubertal timing, sexual activity, and substance use for maltreated versus nonmaltreated adolescents.

PubMed

Negriff, Sonya; Brensilver, Matthew; Trickett, Penelope K

2015-06-01

To test models linking pubertal timing, peer substance use, sexual behavior, and substance use for maltreated versus comparison adolescents. Three theoretical mechanisms were tested: (1) peer influence links early pubertal timing to later sexual behavior and substance use; (2) early maturers engage in substance use on their own and then select substance-using friends; or (3) early maturers initiate sexual behaviors which lead them to substance-using peers. The data came from a longitudinal study of the effects of child maltreatment on adolescent development (303 maltreated and 151 comparison adolescents; age, 9-13 years at initial wave). Multiple-group structural equation models tested the hypotheses across three time points including variables of pubertal timing, perception of peer substance use, sexual behavior, and self-reported substance use. Early pubertal timing was associated with substance-using peers only for maltreated adolescents, indicating the mediation path from early pubertal timing through substance-using peers to subsequent adolescent substance use and sexual behavior only holds for maltreated adolescents. Mediation via sexual behavior was significant for both maltreated and comparison adolescents. This indicates that sexual behavior may be a more universal mechanism linking early maturation with risky friends regardless of adverse life experiences. The findings are a step toward elucidating the developmental pathways from early puberty to risk behavior and identifying early experiences that may alter mediation effects. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Developmental trajectories of brain maturation and behavior: Relevance to major mental illnesses.

PubMed

Lockhart, Sedona; Sawa, Akira; Niwa, Minae

2018-05-01

Adverse events in childhood and adolescence, such as social neglect or drug abuse, are known to lead to behavioral changes in young adulthood. This is particularly true for the subset of people who are intrinsically more vulnerable to stressful conditions. Yet the underlying mechanisms for such developmental trajectory from early life insult to aberrant adult behavior remains elusive. Adolescence is a period of dynamic physiological, psychological, and behavioral changes, encompassing a distinct neurodevelopmental stage called the 'critical period'. During adolescence, the brain is uniquely susceptible to stress. Stress mediators may lead to disturbances to biological processes that can cause permanent alterations in the adult stage, even as severe as the onset of mental illness when paired with genetic risk and environmental factors. Understanding the molecular factors governing the critical period and how stress can disturb the maturation processes will allow for better treatment and prevention of late adolescent/young adult onset psychiatric disorders. Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Correlation among chronologic age, skeletal maturity, and dental age.

PubMed

Sukhia, Rashna H; Fida, Mubassar

2010-01-01

To determine the correlation among chronologic age, skeletal maturity, and dental age in reference to both sexes. In 380 subjects (147 males and 233 females) between 7 and 17 years of age, skeletal maturity was assessed using the cervical vertebral maturation stages described by Baccetti et al. Dental age was determined using the Demirjian method. The correlation between skeletal maturity and chronologic age on one side and between skeletal maturity and dental age on the other was assessed with Spearman rank correlation coefficients. Pearson correlation coefficients were used to assess the correlation between chronologic and dental age. For both sexes, significant correlations among chronologic age, skeletal maturity, and dental age were found. The mandibular first premolar had the highest correlation with skeletal maturation in both sexes. As skeletal maturity and dental age are significantly correlated, tooth development may be used to assess a patient's skeletal maturity at an early age. © 2011 BY QUINTESSENCE PUBLISHING CO, INC.

MicroRNA 665 Regulates Dentinogenesis through MicroRNA-Mediated Silencing and Epigenetic Mechanisms.

PubMed

Heair, Hannah M; Kemper, Austin G; Roy, Bhaskar; Lopes, Helena B; Rashid, Harunur; Clarke, John C; Afreen, Lubana K; Ferraz, Emanuela P; Kim, Eddy; Javed, Amjad; Beloti, Marcio M; MacDougall, Mary; Hassan, Mohammad Q

2015-09-01

Studies of proteins involved in microRNA (miRNA) processing, maturation, and silencing have indicated the importance of miRNAs in skeletogenesis, but the specific miRNAs involved in this process are incompletely defined. Here, we identified miRNA 665 (miR-665) as a potential repressor of odontoblast maturation. Studies with cultured cell lines and primary embryonic cells showed that miR-665 represses the expression of early and late odontoblast marker genes and stage-specific proteases involved in dentin maturation. Notably, miR-665 directly targeted Dlx3 mRNA and decreased Dlx3 expression. Furthermore, RNA-induced silencing complex (RISC) immunoprecipitation and biotin-labeled miR-665 pulldown studies identified Kat6a as another potential target of miR-665. KAT6A interacted physically and functionally with RUNX2, activating tissue-specific promoter activity and prompting odontoblast differentiation. Overexpression of miR-665 reduced the recruitment of KAT6A to Dspp and Dmp1 promoters and prevented KAT6A-induced chromatin remodeling, repressing gene transcription. Taken together, our results provide novel molecular evidence that miR-665 functions in an miRNA-epigenetic regulatory network to control dentinogenesis. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Spatiotemporal dynamics of membrane remodeling and fusion proteins during endocytic transport

PubMed Central

Arlt, Henning; Auffarth, Kathrin; Kurre, Rainer; Lisse, Dominik; Piehler, Jacob; Ungermann, Christian

2015-01-01

Organelles of the endolysosomal system undergo multiple fission and fusion events to combine sorting of selected proteins to the vacuole with endosomal recycling. This sorting requires a consecutive remodeling of the organelle surface in the course of endosomal maturation. Here we dissect the remodeling and fusion machinery on endosomes during the process of endocytosis. We traced selected GFP-tagged endosomal proteins relative to exogenously added fluorescently labeled α-factor on its way from the plasma membrane to the vacuole. Our data reveal that the machinery of endosomal fusion and ESCRT proteins has similar temporal localization on endosomes, whereas they precede the retromer cargo recognition complex. Neither deletion of retromer nor the fusion machinery with the vacuole affects this maturation process, although the kinetics seems to be delayed due to ESCRT deletion. Of importance, in strains lacking the active Rab7-like Ypt7 or the vacuolar SNARE fusion machinery, α-factor still proceeds to late endosomes with the same kinetics. This indicates that endosomal maturation is mainly controlled by the early endosomal fusion and remodeling machinery but not the downstream Rab Ypt7 or the SNARE machinery. Our data thus provide important further understanding of endosomal biogenesis in the context of cargo sorting. PMID:25657322

Oxytocin, a main breastfeeding hormone, prevents hypertension acquired in utero: A therapeutics preview.

PubMed

Vargas-Martínez, Froylán; Schanler, Richard J; Abrams, Steven A; Hawthorne, Keli M; Landers, Susan; Guzman-Bárcenas, José; Muñoz, Onofre; Henriksen, Tore; Petersson, Maria; Uvnäs-Moberg, Kerstin; Jiménez-Estrada, Ismael

2017-01-01

Hypertension is a major risk factor for ischemic heart disease and stroke, leading causes of morbidity and death worldwide. Intrauterine growth restriction (IUGR), caused by an excess of glucocorticoid exposure to the fetus, produces an imbalance in oxidative stress altering many biochemical and epigenetic gene transcription processes exposing the fetus and neonate to the 'thrifty' phenotype and pervasive polymorphisms appearance damaging health, cognitive, and behavioral processes in later life. OT is a major regulator of oxidative stress radicals that plays a major role in neonatal maturation of the central nervous system and many peripheral tissues expressing oxytocin/oxytocin-receptor (OT/OTR) system in the early postnatal period. OT and OTR are damaged by IUGR and early stress. This review highlights the fact that hypertension is likely to be a legacy of preterm birth due to IUGR and failure to meet nutritional needs in early infancy when fed formula instead of breastfeeding or human milk. Copyright © 2016. Published by Elsevier B.V.

Gene-Environment Interplay in the Association between Pubertal Timing and Delinquency in Adolescent Girls

PubMed Central

Harden, K. Paige; Mendle, Jane

2014-01-01

Early pubertal timing places girls at elevated risk for a breadth of negative outcomes, including involvement in delinquent behavior. While previous developmental research has emphasized the unique social challenges faced by early maturing girls, this relation is complicated by genetic influences for both delinquent behavior and pubertal timing, which are seldom controlled for in existing research. The current study uses genetically informed data on 924 female-female twin and sibling pairs drawn from the National Longitudinal Study of Adolescent Health to (1) disentangle biological versus environmental mechanisms for the effects of early pubertal timing and (2) test for gene-environment interactions. Results indicate that early pubertal timing influences girls’ delinquency through a complex interplay between biological risk and environmental experiences. Genes related to earlier age at menarche and higher perceived development significantly predict increased involvement in both non-violent and violent delinquency. Moreover, after accounting for this genetic association between pubertal timing and delinquency, the impact of non-shared environmental influences on delinquency are significantly moderated by pubertal timing, such that the non-shared environment is most important among early maturing girls. This interaction effect is particularly evident for non-violent delinquency. Overall, results suggest early maturing girls are vulnerable to an interaction between genetic and environmental risks for delinquent behavior. PMID:21668078

Weight training in youth-growth, maturation, and safety: an evidence-based review.

PubMed

Malina, Robert M

2006-11-01

To review the effects of resistance training programs on pre- and early-pubertal youth in the context of response, potential influence on growth and maturation, and occurrence of injury. Evidence-based review. Twenty-two reports dealing with experimental resistance training protocols, excluding isometric programs, in pre- and early-pubertal youth, were reviewed in the context of subject characteristics, training protocol, responses, and occurrence of injury. Experimental programs most often used isotonic machines and free weights, 2- and 3-day protocols, and 8- and 12-week durations, with significant improvements in muscular strength during childhood and early adolescence. Strength gains were lost during detraining. Experimental resistance training programs did not influence growth in height and weight of pre- and early-adolescent youth, and changes in estimates of body composition were variable and quite small. Only 10 studies systematically monitored injuries, and only three injuries were reported. Estimated injury rates were 0.176, 0.053, and 0.055 per 100 participant-hours in the respective programs. Experimental training protocols with weights and resistance machines and with supervision and low instructor/participant ratios are relatively safe and do not negatively impact growth and maturation of pre- and early-pubertal youth.

Early events in xenograft development from the human embryonic stem cell line HS181--resemblance with an initial multiple epiblast formation.

PubMed

Gertow, Karin; Cedervall, Jessica; Jamil, Seema; Ali, Rouknuddin; Imreh, Marta P; Gulyas, Miklos; Sandstedt, Bengt; Ahrlund-Richter, Lars

2011-01-01

Xenografting is widely used for assessing in vivo pluripotency of human stem cell populations. Here, we report on early to late events in the development of mature experimental teratoma from a well-characterized human embryonic stem cell (HESC) line, HS181. The results show an embryonic process, increasingly chaotic. Active proliferation of the stem cell derived cellular progeny was detected already at day 5, and characterized by the appearance of multiple sites of engraftment, with structures of single or pseudostratified columnar epithelium surrounding small cavities. The striking histological resemblance to developing embryonic ectoderm, and the formation of epiblast-like structures was supported by the expression of the markers OCT4, NANOG, SSEA-4 and KLF4, but a lack of REX1. The early neural marker NESTIN was uniformly expressed, while markers linked to gastrulation, such as BMP-4, NODAL or BRACHYURY were not detected. Thus, observations on day 5 indicated differentiation comparable to the most early transient cell populations in human post implantation development. Confirming and expanding on previous findings from HS181 xenografts, these early events were followed by an increasingly chaotic development, incorporated in the formation of a benign teratoma with complex embryonic components. In the mature HS181 teratomas not all types of organs/tissues were detected, indicating a restricted differentiation, and a lack of adequate spatial developmental cues during the further teratoma formation. Uniquely, a kinetic alignment of rare complex structures was made to human embryos at diagnosed gestation stages, showing minor kinetic deviations between HS181 teratoma and the human counterpart.

The evolution of predictive adaptive responses in human life history

PubMed Central

Nettle, Daniel; Frankenhuis, Willem E.; Rickard, Ian J.

2013-01-01

Many studies in humans have shown that adverse experience in early life is associated with accelerated reproductive timing, and there is comparative evidence for similar effects in other animals. There are two different classes of adaptive explanation for associations between early-life adversity and accelerated reproduction, both based on the idea of predictive adaptive responses (PARs). According to external PAR hypotheses, early-life adversity provides a ‘weather forecast’ of the environmental conditions into which the individual will mature, and it is adaptive for the individual to develop an appropriate phenotype for this anticipated environment. In internal PAR hypotheses, early-life adversity has a lasting negative impact on the individual's somatic state, such that her health is likely to fail more rapidly as she gets older, and there is an advantage to adjusting her reproductive schedule accordingly. We use a model of fluctuating environments to derive evolveability conditions for acceleration of reproductive timing in response to early-life adversity in a long-lived organism. For acceleration to evolve via the external PAR process, early-life cues must have a high degree of validity and the level of annual autocorrelation in the individual's environment must be almost perfect. For acceleration to evolve via the internal PAR process requires that early-life experience must determine a significant fraction of the variance in survival prospects in adulthood. The two processes are not mutually exclusive, and mechanisms for calibrating reproductive timing on the basis of early experience could evolve through a combination of the predictive value of early-life adversity for the later environment and its negative impact on somatic state. PMID:23843395

Emergence, Development, and Maturity of the Gonad of Two Species of Chitons “Sea Cockroach” (Mollusca: Polyplacophora) through the Early Life Stages

PubMed Central

Avila-Poveda, Omar Hernando; Abadia-Chanona, Quetzalli Yasú

2013-01-01

This study describes and recognises, using histological and microscopical examinations on a morphometrical basis, several gonad traits through the early life stages of Chiton articulatus and C. albolineatus. Gonadal ontogenesis, gonad development stages, sexual differentiation, onset of the first sexual maturity, and growth sequences or “early life stages” were determined. In addition, allometry between lengths and body weight pooled for both sexes per each chiton were calculated using equation Y = aXb. A total of 125 chitons (4≤TL≤40 mm, in total length “TL”) were used. All allometric relations showed a strong positive correlation (r), close to 1, with b-values above three, indicating an isometric growth. Gonadal ontogenesis and gonad development stages were categorised into three periods (“Pw” without gonad, “Pe” gonad emergence, and “Pf” gonadal sac formed) and four stages (“S0” gametocytogenesis, “S1” gametogenesis, “S2” mature, and “S3” spawning), respectively. Compound digital images were attained for each process. Periods and stages are overlapped among them and between species, with the following overall confidence intervals in TL: Pw 6.13–14.32 mm, Pe 10.32–16.93 mm, Pf 12.99–25.01 mm, S0 16.08–24.34 mm (females) and 19.51–26.60 mm (males), S1 27.15–35.63 mm (females) and 23.45–32.27 mm (males), S2 24.48–40.24 mm (females) and 25.45–32.87 mm (males). Sexual differentiation (in S0) of both chitons occurs first as a female then as a male; although, males reach the onset of the first sexual maturity earlier than females, thus for C. articulatus males at 17 mm and females at 32 mm, and for C. albolineatus males at 23.5 mm and females at 28 mm, all in TL. Four early life stages (i.e., subjuvenile, juvenile, subadult, and adult) are described and proposed to distinguish growth sequences. Our results may be useful to diverse disciplines, from developmental biology to fisheries management. PMID:23936353

Pubertal development, spare time activities, and adolescent delinquency: testing the contextual amplification hypothesis.

PubMed

Kretschmer, Tina; Oliver, Bonamy R; Maughan, Barbara

2014-08-01

Extensive evidence supports associations between early pubertal timing and adolescent externalizing behavior, but how and under which conditions they are linked is not fully understood. In addition, pubertal development is also characterized by variations in the relative speed at which individuals mature, but studies linking pubertal 'tempo' and outcomes are scarce. This study examined the mediating and moderating roles of spare time activities in associations between pubertal development and later delinquency, using data from a large (4,327 girls, 4,250 boys) longitudinal UK cohort (Avon Longitudinal Study of Parents and Children). Self-reports of Tanner stage were available from ages 9 to 14, spare time activities at age 12 and delinquency at age 15. Pubertal development was examined using latent growth models. Spare time activities were categorized using factor analyses, yielding four types (hanging out at home, hanging out outside, consumerist behavior, and sports/games), which were examined as mediators and moderators. Earlier and faster maturation predicted delinquency in boys and girls. Spare time activities partially mediated these links such that early maturing girls more often engaged in hanging out outside, which placed them at greater risk for delinquency. In addition, compared to their later and slower maturing counterparts, boys who matured earlier and faster were less likely to engage in sports/games, a spare time activity type that is linked to lower delinquency risk. No moderation effects were found. The findings extend previous research on outcomes of early maturation and show how spare time activities act as proxies between pubertal development and delinquency.

Cannabinoid Receptors Modulate Neuronal Morphology and AnkyrinG Density at the Axon Initial Segment

PubMed Central

Tapia, Mónica; Dominguez, Ana; Zhang, Wei; del Puerto, Ana; Ciorraga, María; Benitez, María José; Guaza, Carmen; Garrido, Juan José

2017-01-01

Neuronal polarization underlies the ability of neurons to integrate and transmit information. This process begins early in development with axon outgrowth, followed by dendritic growth and subsequent maturation. In between these two steps, the axon initial segment (AIS), a subcellular domain crucial for generating action potentials (APs) and maintaining the morphological and functional polarization, starts to develop. However, the cellular/molecular mechanisms and receptors involved in AIS initial development and maturation are mostly unknown. In this study, we have focused on the role of the type-1 cannabinoid receptor (CB1R), a highly abundant G-protein coupled receptor (GPCR) in the nervous system largely involved in different phases of neuronal development and differentiation. Although CB1R activity modulation has been related to changes in axons or dendrites, its possible role as a modulator of AIS development has not been yet explored. Here we analyzed the potential role of CB1R on neuronal morphology and AIS development using pharmacological and RNA interference approaches in cultured hippocampal neurons. CB1R inhibition, at a very early developmental stage, has no effect on axonal growth, yet CB1R activation can promote it. By contrast, subsequent dendritic growth is impaired by CB1R inhibition, which also reduces ankyrinG density at the AIS. Moreover, our data show a significant correlation between early dendritic growth and ankyrinG density. However, CB1R inhibition in later developmental stages after dendrites are formed only reduces ankyrinG accumulation at the AIS. In conclusion, our data suggest that neuronal CB1R basal activity plays a role in initial development of dendrites and indirectly in AIS proteins accumulation. Based on the lack of CB1R expression at the AIS, we hypothesize that CB1R mediated modulation of dendritic arbor size during early development indirectly determines the accumulation of ankyrinG and AIS development. Further studies will be necessary to determine which CB1R-dependent mechanisms can coordinate these two domains, and what may be the impact of these early developmental changes once neurons mature and are embedded in a functional brain network. PMID:28179879

Serotonin-related pathways and developmental plasticity: relevance for psychiatric disorders

PubMed Central

Dayer, Alexandre

2014-01-01

Risk for adult psychiatric disorders is partially determined by early-life alterations occurring during neural circuit formation and maturation. In this perspective, recent data show that the serotonin system regulates key cellular processes involved in the construction of cortical circuits. Translational data for rodents indicate that early-life serotonin dysregulation leads to a wide range of behavioral alterations, ranging from stress-related phenotypes to social deficits. Studies in humans have revealed that serotonin-related genetic variants interact with early-life stress to regulate stress-induced cortisol responsiveness and activate the neural circuits involved in mood and anxiety disorders. Emerging data demonstrate that early-life adversity induces epigenetic modifications in serotonin-related genes. Finally, recent findings reveal that selective serotonin reuptake inhibitors can reinstate juvenile-like forms of neural plasticity, thus allowing the erasure of long-lasting fear memories. These approaches are providing new insights on the biological mechanisms and clinical application of antidepressants. PMID:24733969

Early Puberty, Negative Peer Influence, and Problem Behaviors in Adolescent Girls

PubMed Central

Elliott, Marc N.; Davies, Susan; Tortolero, Susan R.; Cuccaro, Paula; Schuster, Mark A.

2014-01-01

OBJECTIVE: To determine how early puberty and peer deviance relate to trajectories of aggressive and delinquent behavior in early adolescence and whether these relationships differ by race/ethnicity. METHODS: In this longitudinal study, 2607 girls from 3 metropolitan areas and their parents were interviewed at ages 11, 13, and 16 years. Girls reported on their age of onset of menarche, best friend’s deviant behavior, delinquency, and physical, relational, and nonphysical aggression. Parents provided information on family sociodemographic characteristics and girls’ race/ethnicity. RESULTS: Sixteen percent of girls were classified as early maturers (defined by onset of menarche before age 11 years). Overall, relational and nonphysical aggression increased from age 11 to age 16, whereas delinquency and physical aggression remained stable. Early puberty was associated with elevated delinquency and physical aggression at age 11. The relationship with early puberty diminished over time for physical aggression but not for delinquency. Best friend’s deviant behavior was linked with higher levels of all problem behaviors, but the effect lessened over time for most outcomes. Early puberty was associated with a stronger link between best friend’s deviance and delinquency, suggesting increased vulnerability to negative peer influences among early-maturing girls. A similar vulnerability was observed for relational and nonphysical aggression among girls in the “other” racial/ethnic minority group only. CONCLUSIONS: Early puberty and friends’ deviance may increase the risk of problem behavior in young adolescent girls. Although many of these associations dissipate over time, early-maturing girls are at risk of persistently higher delinquency and stronger negative peer influences. PMID:24324002

Wheat seed weight and quality differ temporally in sensitivity to warm or cool conditions during seed development and maturation

PubMed Central

Nasehzadeh, M

2017-01-01

Abstract Background and aims Short periods of extreme temperature may affect wheat (Triticum aestivum) seed weight, but also quality. Temporal sensitivity to extreme temperature during seed development and maturation was investigated. Methods Plants of ‘Tybalt’ grown at ambient temperature were moved to growth cabinets at 29/20°C or 34/20°C (2010), or 15/10°C or 34/20°C (2011), for successive 7-d periods from 7 DAA (days after anthesis) onwards, and also 7–65 DAA in 2011. Seed samples were harvested serially and moisture content, weight, ability to germinate, subsequent longevity in air-dry storage and bread-making quality were determined. Key Results High temperature (34/20°C) reduced final seed weight, with greatest temporal sensitivity at 7–14 or 14–21 DAA. Several aspects of bread-making quality were also most sensitive to high temperature then, but whereas protein quality decreased protein and sulphur concentrations improved. Early exposure to high temperature provided earlier development of ability to germinate and tolerate desiccation, but had little effect on maximum germination capacity. All treatments at 15/10°C resulted in ability to germinate declining between 58 and 65 DAA. Early exposure to high temperature hastened improvement in seed storage longevity, but the subsequent decline in late maturation preceded that in the control. Long (7–65 DAA) exposure to 15/10°C disrupted the development of seed longevity, with no improvement after seed filling ended. Longevity improved during maturation drying in other treatments. Early (7–14 DAA) exposure to high temperature reduced and low temperature increased subsequent longevity at harvest maturity, whereas late (35 or 42–49 DAA) exposure to high temperature increased and low temperature reduced it. Conclusions Temporal sensitivity to extreme temperature was detected. It varied considerably amongst the contrasting seed variables investigated. Subsequent seed longevity at harvest maturity responded negatively to temperature early in development, but positively later in development and throughout maturation. PMID:28637252

Early-Life Nutrition and Neurodevelopment: Use of the Piglet as a Translational Model12

PubMed Central

Mudd, Austin T

2017-01-01

Optimal nutrition early in life is critical to ensure proper structural and functional development of infant organ systems. Although pediatric nutrition historically has emphasized research on the relation between nutrition, growth rates, and gastrointestinal maturation, efforts increasingly have focused on how nutrition influences neurodevelopment. The provision of human milk is considered the gold standard in pediatric nutrition; thus, there is interest in understanding how functional nutrients and bioactive components in milk may modulate developmental processes. The piglet has emerged as an important translational model for studying neurodevelopmental outcomes influenced by pediatric nutrition. Given the comparable nutritional requirements and strikingly similar brain developmental patterns between young pigs and humans, the piglet is being used increasingly in developmental nutritional neuroscience studies. The piglet primarily has been used to assess the effects of dietary fatty acids and their accretion in the brain throughout neurodevelopment. However, recent research indicates that other dietary components, including choline, iron, cholesterol, gangliosides, and sialic acid, among other compounds, also affect neurodevelopment in the pig model. Moreover, novel analytical techniques, including but not limited to MRI, behavioral assessments, and molecular quantification, allow for a more holistic understanding of how nutrition affects neurodevelopmental patterns. By combining early-life nutritional interventions with innovative analytical approaches, opportunities abound to quantify factors affecting neurodevelopmental trajectories in the neonate. This review discusses research using the translational pig model with primary emphasis on early-life nutrition interventions assessing neurodevelopment outcomes, while also discussing nutritionally-sensitive methods to characterize brain maturation. PMID:28096130

The Role of a Relative Age Effect in the 7th International Children’s Winter Games 2016 and the Influence of Biological Maturity Status on Selection

PubMed Central

Müller, Lisa; Hildebrandt, Carolin; Raschner, Christian

2017-01-01

The aim of this study was to analyse the role of a relative age effect (RAE) and to investigate the influence of biological maturity status on the RAE at the 7th International Children`s Winter Games. The birth dates of all 572 participants (365 males, 207 females) were analysed, and the biological maturity status of 384 athletes (243 males, 141 females) was assessed by the age at peak height velocity (APHV) method. A RAE was present in the total sample (χ2 = 67.81; p < 0.001), and among both male (χ2 = 49.02; p < 0.001) and female athletes (χ2 = 37.00; p < 0.001) as well as for strength- (χ2 = 56.46; p < 0.001), endurance- (χ2 = 20.48; p = 0.039) and technique-related types of sports (χ2 = 20.48; p = 0.041). No significant differences in biological maturity status were present between the male athletes of single relative age quarters. Among the female athletes a significant difference was present (F = 5.94, p < 0.001); relatively younger female athletes had significantly lower values in the APHV, which indicated that they were maturing earlier. However, when dividing the athletes into normal, early and late maturing athletes, it could be seen that among the relatively younger athletes, hardly any late maturing athletes were present. These findings revealed that relatively younger athletes seemed to only have a chance for selection if they were early maturing, whereas relatively older athletes had an increased likelihood for selection independent of their biological maturity status. In the future, the relative age and the biological maturity status should be considered in the talent development system for various types of winter sport, to contribute to more fairness and to not discriminate against relatively younger and less mature athletes. Key points The relative age strongly influenced the participation rate at the 7th ICG in 2016. A highly significant RAE was present among male and female participants and among athletes of all three groups of sport disciplines: strength-, endurance- and technique-related types of sport. A significant influence of the biological maturity status on the selection was present among female participants – relatively younger female athletes were more mature than relatively older athletes. Relatively younger male and female athletes seem to only have a chance for selection for the Games if they are early maturing, whereas relatively older athletes have an increased likelihood for selection independent of their biological maturity status. In the future, the biological maturity status and the relative age should be considered in the talent development system for various types of winter sport, to contribute to more fairness and to not discriminate against relatively younger and less mature athletes. PMID:28630572

A longitudinal examination of the influence of maturation on physical self-perceptions and the relationship with physical activity in early adolescent girls.

PubMed

Knowles, Ann-Marie; Niven, Ailsa G; Fawkner, Samantha G; Henretty, Joan M

2009-06-01

This longitudinal study investigated the influence of maturation on physical self-perceptions and the relationship with physical activity in early adolescent girls (N=150; mean age=12.79+/-0.31). Physical characteristics were measured and participants completed the Physical Activity Questionnaire for Children, the Children and Youth Physical Self-Perception Profile and the Pubertal Development Scale on two occasions 12 months apart. The results demonstrated a decrease in overall physical activity levels over 12 months which was not influenced by maturational status or physical characteristics. Additional analysis indicated that physical self-perceptions partially accounted for the explained variance in physical activity change, with physical condition being an important individual predictor of physical activity. Further analysis indicated that body mass was an important individual predictor of changes in perceptions of body attractiveness and physical self-worth. At this age maturation has a limited influence on the physical activity behaviours of early adolescent girls and although the variance in physical activity was partly accounted for by physical self-perceptions, this was a relatively small contribution and other factors related to this drop in physical activity need to be considered longitudinally.

Auditory attention in childhood and adolescence: An event-related potential study of spatial selective attention to one of two simultaneous stories.

PubMed

Karns, Christina M; Isbell, Elif; Giuliano, Ryan J; Neville, Helen J

2015-06-01

Auditory selective attention is a critical skill for goal-directed behavior, especially where noisy distractions may impede focusing attention. To better understand the developmental trajectory of auditory spatial selective attention in an acoustically complex environment, in the current study we measured auditory event-related potentials (ERPs) across five age groups: 3-5 years; 10 years; 13 years; 16 years; and young adults. Using a naturalistic dichotic listening paradigm, we characterized the ERP morphology for nonlinguistic and linguistic auditory probes embedded in attended and unattended stories. We documented robust maturational changes in auditory evoked potentials that were specific to the types of probes. Furthermore, we found a remarkable interplay between age and attention-modulation of auditory evoked potentials in terms of morphology and latency from the early years of childhood through young adulthood. The results are consistent with the view that attention can operate across age groups by modulating the amplitude of maturing auditory early-latency evoked potentials or by invoking later endogenous attention processes. Development of these processes is not uniform for probes with different acoustic properties within our acoustically dense speech-based dichotic listening task. In light of the developmental differences we demonstrate, researchers conducting future attention studies of children and adolescents should be wary of combining analyses across diverse ages. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Auditory attention in childhood and adolescence: An event-related potential study of spatial selective attention to one of two simultaneous stories

PubMed Central

Karns, Christina M.; Isbell, Elif; Giuliano, Ryan J.; Neville, Helen J.

2015-01-01

Auditory selective attention is a critical skill for goal-directed behavior, especially where noisy distractions may impede focusing attention. To better understand the developmental trajectory of auditory spatial selective attention in an acoustically complex environment, in the current study we measured auditory event-related potentials (ERPs) in human children across five age groups: 3–5 years; 10 years; 13 years; 16 years; and young adults using a naturalistic dichotic listening paradigm, characterizing the ERP morphology for nonlinguistic and linguistic auditory probes embedded in attended and unattended stories. We documented robust maturational changes in auditory evoked potentials that were specific to the types of probes. Furthermore, we found a remarkable interplay between age and attention-modulation of auditory evoked potentials in terms of morphology and latency from the early years of childhood through young adulthood. The results are consistent with the view that attention can operate across age groups by modulating the amplitude of maturing auditory early-latency evoked potentials or by invoking later endogenous attention processes. Development of these processes is not uniform for probes with different acoustic properties within our acoustically dense speech-based dichotic listening task. In light of the developmental differences we demonstrate, researchers conducting future attention studies of children and adolescents should be wary of combining analyses across diverse ages. PMID:26002721

Mature clustered, regularly interspaced, short palindromic repeats RNA (crRNA) length is measured by a ruler mechanism anchored at the precursor processing site.

PubMed

Hatoum-Aslan, Asma; Maniv, Inbal; Marraffini, Luciano A

2011-12-27

Precise RNA processing is fundamental to all small RNA-mediated interference pathways. In prokaryotes, clustered, regularly interspaced, short palindromic repeats (CRISPR) loci encode small CRISPR RNAs (crRNAs) that protect against invasive genetic elements by antisense targeting. CRISPR loci are transcribed as a long precursor that is cleaved within repeat sequences by CRISPR-associated (Cas) proteins. In many organisms, this primary processing generates crRNA intermediates that are subject to additional nucleolytic trimming to render mature crRNAs of specific lengths. The molecular mechanisms underlying this maturation event remain poorly understood. Here, we defined the genetic requirements for crRNA primary processing and maturation in Staphylococcus epidermidis. We show that changes in the position of the primary processing site result in extended or diminished maturation to generate mature crRNAs of constant length. These results indicate that crRNA maturation occurs by a ruler mechanism anchored at the primary processing site. We also show that maturation is mediated by specific cas genes distinct from those genes involved in primary processing, showing that this event is directed by CRISPR/Cas loci.

Repression of Osteoblast Maturation by ERRα Accounts for Bone Loss Induced by Estrogen Deficiency

PubMed Central

Gallet, Marlène; Saïdi, Soraya; Haÿ, Eric; Photsavang, Johann; Marty, Caroline; Sailland, Juliette; Carnesecchi, Julie; Tribollet, Violaine; Barenton, Bruno; Forcet, Christelle; Birling, Marie-Christine; Sorg, Tania; Chassande, Olivier; Cohen-Solal, Martine; Vanacker, Jean-Marc

2013-01-01

ERRα is an orphan member of the nuclear receptor family, the complete inactivation of which confers resistance to bone loss induced by ageing and estrogen withdrawal to female mice in correlation with increased bone formation in vivo. Furthermore ERRα negatively regulates the commitment of mesenchymal cells to the osteoblast lineage ex vivo as well as later steps of osteoblast maturation. We searched to determine whether the activities of ERRα on osteoblast maturation are responsible for one or both types of in vivo induced bone loss. To this end we have generated conditional knock out mice in which the receptor is normally present during early osteoblast differentiation but inactivated upon osteoblast maturation. Bone ageing in these animals was similar to that observed for control animals. In contrast conditional ERRαKO mice were completely resistant to bone loss induced by ovariectomy. We conclude that the late (maturation), but not early (commitment), negative effects of ERRα on the osteoblast lineage contribute to the reduced bone mineral density observed upon estrogen deficiency. PMID:23359549

Evidence of size-selective evolution in the fighting conch from prehistoric subsistence harvesting.

PubMed

O'Dea, Aaron; Shaffer, Marian Lynne; Doughty, Douglas R; Wake, Thomas A; Rodriguez, Felix A

2014-05-07

Intensive size-selective harvesting can drive evolution of sexual maturity at smaller body size. Conversely, prehistoric, low-intensity subsistence harvesting is not considered an effective agent of size-selective evolution. Uniting archaeological, palaeontological and contemporary material, we show that size at sexual maturity in the edible conch Strombus pugilis declined significantly from pre-human (approx. 7 ka) to prehistoric times (approx. 1 ka) and again to the present day. Size at maturity also fell from early- to late-prehistoric periods, synchronous with an increase in harvesting intensity as other resources became depleted. A consequence of declining size at maturity is that early prehistoric harvesters would have received two-thirds more meat per conch than contemporary harvesters. After exploring the potential effects of selection biases, demographic shifts, environmental change and habitat alteration, these observations collectively implicate prehistoric subsistence harvesting as an agent of size-selective evolution with long-term detrimental consequences. We observe that contemporary populations that are protected from harvesting are slightly larger at maturity, suggesting that halting or even reversing thousands of years of size-selective evolution may be possible.

Evidence of size-selective evolution in the fighting conch from prehistoric subsistence harvesting

PubMed Central

O'Dea, Aaron; Shaffer, Marian Lynne; Doughty, Douglas R.; Wake, Thomas A.; Rodriguez, Felix A.

2014-01-01

Intensive size-selective harvesting can drive evolution of sexual maturity at smaller body size. Conversely, prehistoric, low-intensity subsistence harvesting is not considered an effective agent of size-selective evolution. Uniting archaeological, palaeontological and contemporary material, we show that size at sexual maturity in the edible conch Strombus pugilis declined significantly from pre-human (approx. 7 ka) to prehistoric times (approx. 1 ka) and again to the present day. Size at maturity also fell from early- to late-prehistoric periods, synchronous with an increase in harvesting intensity as other resources became depleted. A consequence of declining size at maturity is that early prehistoric harvesters would have received two-thirds more meat per conch than contemporary harvesters. After exploring the potential effects of selection biases, demographic shifts, environmental change and habitat alteration, these observations collectively implicate prehistoric subsistence harvesting as an agent of size-selective evolution with long-term detrimental consequences. We observe that contemporary populations that are protected from harvesting are slightly larger at maturity, suggesting that halting or even reversing thousands of years of size-selective evolution may be possible. PMID:24648229

Developmental and ethnic issues experienced by emerging adult African American women related to developing a mature love relationship.

PubMed

Tyson, Sheryl Y

2012-01-01

This qualitative study explored perspectives of emerging adult African American women on the development of mature love relationships. Inductive analysis of focus group interviews, conducted with a purposive sample of 31 African American women, yielded themes related to relationship goals and characteristics, and interpersonal and societal challenges to finding the right partner and developing a mature love relationship. Core categories that emerged from analysis of the discussions were (1) age and relationship goal differences within the emerging adult group, (2) mature love relationship goals and characteristics, (3) interpersonal obstacles to finding the right partner, and (4) societal obstacles to finding the right partner. Two approaches-black womanist/feminist thought (Collins, 2000 ; Walker, 1983 ) and relationship maturity theory (Paul & White, 1990 )-were then combined to explain the influence of historic and contemporary interpersonal and societal factors on developmental and ethnic issues that challenge positive gender identity formation, hasten intimacy maturity, and hinder the development of mature love relationships among emerging adult African American women. For these women, premature responsibility, especially early caregiver burden, was related to the early development of intimacy capacity and the desire for a mature love relationship, to be protected, and to have someone to help carry the load. Interracial dating, negative stereotypic images of African American women, and even positive images of enduring black love relationships posed difficult challenges to positive identity formation and intimacy maturity. A primary challenge was to counteract negative stereotypic images, so that they could develop their own self-identities as women and as relationship partners.

Effect of maturity and hybrid on ruminal and intestinal digestion of corn silage in dry cows.

PubMed

Peyrat, J; Baumont, R; Le Morvan, A; Nozière, P

2016-01-01

The aim of this study was to evaluate the effect of stage of maturity at harvest on extent of starch, neutral detergent fiber (NDF), and protein digestion, and rumen fermentation in dry cows fed whole-plant corn silage from different hybrids. Four nonlactating Holstein cows cannulated at the rumen and proximal duodenum were fed 4 corn silages differing in hybrid (flint vs. flint-dent) and maturity stage (early vs. late) in a 4 × 4 Latin square design. From early to late maturity, starch content increased (from 234.5 to 348.5 g/kg), whereas total-tract (99.7 to 94.5%) and ruminal starch digestibility (91.3 to 86.5%) decreased significantly. The decrease in ruminal starch digestibility with increasing maturity was similar between hybrids. No effects were found of maturity, hybrid, or maturity × hybrid interaction on total-tract NDF digestibility, ruminal NDF digestibility, true digestibility of N and organic matter in the rumen, or microbial synthesis. Harvesting at later maturity led to increased ruminal ammonia, total volatile fatty acid concentrations, and acetate/propionate ratio but not pH. This study concludes that delaying date of harvest modifies the proportions of digestible starch and NDF supplied to cattle. Adjusting date of corn harvest to modulate amount of rumen-digested starch could be used as a strategy to control nutrient delivery to ruminants. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Population parameters for resistance to Fusarium graminearum and Fusarium verticillioides ear rot among large sets of early, mid-late and late maturing European maize (Zea mays L.) inbred lines.

PubMed

Löffler, Martin; Kessel, Bettina; Ouzunova, Milena; Miedaner, Thomas

2010-03-01

Infection of maize ears with Fusarium graminearum (FG) and Fusarium verticillioides (FV) reduces yield and quality by mycotoxin contamination. Breeding and growing varieties resistant to both Fusarium spp. is the best alternative to minimize problems. The objectives of our study were to draw conclusions on breeding for ear rot resistance by estimating variance components, heritabilities and correlations between resistances to FV and FG severity and to investigate different inoculation methods. In 2007 and 2008, three maturity groups (early, mid-late, late) each comprising about 150 inbred lines were tested in Germany, France, Italy, and Hungary according to their maturity group. They were silk channel inoculated by FG (early) and FV (all groups). In the late maturity group, additionally kernel inoculation was applied in a separate trial. The percentage of mycelium coverage on the ear was rated at harvest (0-100%). Significant (P < 0.01) genotypic variances of ear rot severity were found in all groups. Inoculation was superior to natural infection because of higher disease severities and heritabilities. In early maturing flints and dents, FG caused significantly (P < 0.01) higher ear rot severity than FV (61.7 and 55.1% FG vs. 18.2 and 11.1% FV ear rot severity, respectively). FV inoculation in Southern Europe (mid-late, late) resulted in similar means between 10.3 and 14.0%. Selection is complicated by significant (P < 0.01) genotype x environment interactions. Correlation between FG and FV severity was moderate in flints and dents (r = 0.59 and 0.49, respectively) but lines resistant to both fungi exist. We conclude that chances for selecting improved European elite maize material within the existing germplasms is promising by multi-environmental inoculation trials.

Influence of thyroid in nervous system growth.

PubMed

Mussa, G C; Mussa, F; Bretto, R; Zambelli, M C; Silvestro, L

2001-08-01

Nervous system growth and differentiation are closely correlated with the presence of iodine and thyroid hormones in initial development stages. In the human species, encephalon maturation during the first quarter of pregnancy is affected according to recent studies by the transplacenta passage of maternal thyroid hormones while it depends on initial iodiothyronin secretion by the foetal gland after the 12th week of pregnancy. Thyroid hormone deficiency during nervous system development causes altered noble nervous cells, such as the pyramidal cortical and Purkinje cells, during glial cell proliferation and differentiation alike. Neurons present cell hypoplasia with reduced axon count, dendritic branching, synaptic spikes and interneuron connections. Oligodendrocytes decrease in number and average myelin content consequently drops. Biochemical studies on hypothyroid rats have demonstrated alterations to neuron intraplasmatic microtubule content and organisation, changed mitochondria number and arrangement and anomalies in T3 nuclear and citoplasmatic receptor maturation. Alterations to microtubules are probably responsible for involvement of the axon-dendrite system, and are the consequence of deficient thyroid hormone action on the mitochondria, the mitochondria enzymes and proteins associated with microtubules. Nuclear and citoplasmatic receptors have been identified and gene clonation studies have shown two families of nuclear receptors that include several sub-groups in their turn. A complex scheme of temporal and spatial expression of these receptors exists, so they probably contribute with one complementary function, although their physiological role differs. The action of thyroid hormones occurs by changing cell protein levels because of their regulation at the transcriptional or post-transcriptional level. Genes submitted to thyroid hormone control are either expressed by oligodendrytes, which are myelin protein coders or glial differentiation mediators, or are nervous cell specific, genes coding neurotropins or proteins involved in synaptic excitation. The use of new PMRS and MRI non-invasive techniques has enabled identification of metabolic and biochemical markers for alterations in the encephalon of untreated hypothyroid children. Even an excess of thyroid hormones during early nervous system development can cause permanent effects. Hyperthyroidism in fact initially induces accelerated maturation process including cell migration and differentiation, extension of dendritic processes and synaptogenesis but a later excess of thyroid hormones causes reduction of the total number of dendritic spikes, due to early interruption of neuron proliferation. Experimental studies and clinical research have clarified not only the correlation between nervous system maturation and thyroid function during early development stages and the certain finding from this research is that both excess and deficient thyroid hormones can cause permanent anatomo-functional alterations to the nervous system.

Family, Peer, and Pubertal Determinants of Dating Involvement Among Adolescents

PubMed Central

Low, Sabina; Shortt, Joann Wu

2017-01-01

This study examines the influence of family, peer, and biological contributors to dating involvement among early adolescents (11–14 years of age; n = 244). Further, we assess how parental monitoring may be modified by pubertal maturation and older sibling risky behavior. Data on delinquent peer affiliation, pubertal maturation, parental monitoring, older sibling risky behavior, and dating involvement were gathered through observations and surveys from adolescents, mothers, older siblings, and teachers. Results indicate that lower levels of parental monitoring and higher levels of older sibling risky behavior were related to adolescents’ dating involvement through delinquent peer affiliation. Pubertal maturation was directly related to dating involvement for early daters. Findings emphasize the value of examining social and biological factors, in concert, over time. PMID:28498528

Determinants of relative skeletal maturity in South African children.

PubMed

Hawley, Nicola L; Rousham, Emily K; Johnson, William; Norris, Shane A; Pettifor, John M; Cameron, Noël

2012-01-01

The variation of skeletal maturity about chronological age is a sensitive indicator of population health. Age appropriate or advanced skeletal maturity is a reflection of adequate environmental and social conditions, whereas delayed maturation suggests inadequate conditions for optimal development. There remains a paucity of data, however, to indicate which specific biological and environmental factors are associated with advancement or delay in skeletal maturity. The present study utilises longitudinal data from the South African Birth to Twenty (Bt20) study to indentify predictors of relative skeletal maturity (RSM) in early adolescence. A total of 244 black South African children (n=131 male) were included in this analysis. Skeletal maturity at age 9/10 years was assessed using the Tanner and Whitehouse III RUS technique. Longitudinal data on growth, socio-economic position and pubertal development were entered into sex-specific multivariable general linear regression models with relative skeletal maturity (skeletal age-chronological age) as the outcome. At 9/10 years of age males showed an average of 0.66 years delay in skeletal maturation relative to chronological age. Females showed an average of 1.00 year delay relative to chronological age. In males, being taller at 2 years (p<0.01) and heavier at 2 years (p<0.01) predicted less delay in RSM at age 9/10 years, independent of current size and body composition. In females, both height at 2 years and conditional weight at 2 years predicted less delay in RSM at 9/10 years (p<0.05) but this effect was mediated by current body composition. Having greater lean mass at 9/10 years was associated with less delayed RSM in females (p<0.01) as was pubertal status at the time of skeletal maturity assessment (p<0.01). This study identifies several predictors of skeletal maturation at 9/10 years, indicating a role for early life exposures in determining the rate of skeletal maturation during childhood independently of current stature. Copyright © 2011 Elsevier Inc. All rights reserved.

The Early Identity Exploration Scale-a measure of initial exploration in breadth during early adolescence.

PubMed

Kłym, Maria; Cieciuch, Jan

2015-01-01

The existing models and measurement instruments concerning identity appear to primarily focus on adolescence and early adulthood, and studies extending identity research to younger stages of life are scarce. There has been a particular lack of instruments measuring the early stages of identity formation, especially the process of exploration, which has been portrayed as a central process during this particular period of life. Our aim is to help fill the gap in the literature and facilitate further studies of the exploration process by providing an appropriate instrument to measure exploration in breadth during early adolescence. As a coherent and mature sense of identity is closely associated with psychosocial well-being, an effective identity exploration scale will enable researchers to assess the predictors of young adolescents' well-being. We propose a model of identity exploration domains based on the literature and considering 12 exploration domains: physical appearance, free time, family, work, boyfriend-girlfriend relationships, own opinion formation, perception of own place in the life cycle, self-reflection, future, future family, outlook on life, and attitude toward rules. The study was conducted on a group of N = 454 adolescents (50% males, M age = 13.04, SD = 0.98). Both reliability and structural validity, as verified by confirmatory factor analysis were satisfactory. The instrument is invariant across gender groups at the scalar level of measurement invariance.

The Early Identity Exploration Scale—a measure of initial exploration in breadth during early adolescence

PubMed Central

Kłym, Maria; Cieciuch, Jan

2015-01-01

The existing models and measurement instruments concerning identity appear to primarily focus on adolescence and early adulthood, and studies extending identity research to younger stages of life are scarce. There has been a particular lack of instruments measuring the early stages of identity formation, especially the process of exploration, which has been portrayed as a central process during this particular period of life. Our aim is to help fill the gap in the literature and facilitate further studies of the exploration process by providing an appropriate instrument to measure exploration in breadth during early adolescence. As a coherent and mature sense of identity is closely associated with psychosocial well-being, an effective identity exploration scale will enable researchers to assess the predictors of young adolescents' well-being. We propose a model of identity exploration domains based on the literature and considering 12 exploration domains: physical appearance, free time, family, work, boyfriend-girlfriend relationships, own opinion formation, perception of own place in the life cycle, self-reflection, future, future family, outlook on life, and attitude toward rules. The study was conducted on a group of N = 454 adolescents (50% males, Mage = 13.04, SD = 0.98). Both reliability and structural validity, as verified by confirmatory factor analysis were satisfactory. The instrument is invariant across gender groups at the scalar level of measurement invariance. PMID:25983707

The Splicing ATPase Prp43p Is a Component of Multiple Preribosomal Particles

PubMed Central

Lebaron, Simon; Froment, Carine; Fromont-Racine, Micheline; Rain, Jean-Christophe; Monsarrat, Bernard; Caizergues-Ferrer, Michèle; Henry, Yves

2005-01-01

Prp43p is a putative helicase of the DEAH family which is required for the release of the lariat intron from the spliceosome. Prp43p could also play a role in ribosome synthesis, since it accumulates in the nucleolus. Consistent with this hypothesis, we find that depletion of Prp43p leads to accumulation of 35S pre-rRNA and strongly reduces levels of all downstream pre-rRNA processing intermediates. As a result, the steady-state levels of mature rRNAs are greatly diminished following Prp43p depletion. We present data arguing that such effects are unlikely to be solely due to splicing defects. Moreover, we demonstrate by a combination of a comprehensive two-hybrid screen, tandem-affinity purification followed by mass spectrometry, and Northern analyses that Prp43p is associated with 90S, pre-60S, and pre-40S ribosomal particles. Prp43p seems preferentially associated with Pfa1p, a novel specific component of pre-40S ribosomal particles. In addition, Prp43p interacts with components of the RNA polymerase I (Pol I) transcription machinery and with mature 18S and 25S rRNAs. Hence, Prp43p might be delivered to nascent 90S ribosomal particles during pre-rRNA transcription and remain associated with preribosomal particles until their final maturation steps in the cytoplasm. Our data also suggest that the ATPase activity of Prp43p is required for early steps of pre-rRNA processing and normal accumulation of mature rRNAs. PMID:16227579

Unfertilized frog eggs die by apoptosis following meiotic exit

PubMed Central

2011-01-01

Background A characteristic feature of frog reproduction is external fertilization accomplished outside the female's body. Mature fertilization-competent frog eggs are arrested at the meiotic metaphase II with high activity of the key meiotic regulators, maturation promoting factor (MPF) and cytostatic factor (CSF), awaiting fertilization. If the eggs are not fertilized within several hours of ovulation, they deteriorate and ultimately die by as yet unknown mechanism. Results Here, we report that the vast majority of naturally laid unfertilized eggs of the African clawed frog Xenopus laevis spontaneously exit metaphase arrest under various environmental conditions and degrade by a well-defined apoptotic process within 48 hours after ovulation. The main features of this process include cytochrome c release, caspase activation, ATP depletion, increase of ADP/ATP ratio, apoptotic nuclear morphology, progressive intracellular acidification, and egg swelling. Meiotic exit seems to be a prerequisite for execution of the apoptotic program, since (i) it precedes apoptosis, (ii) apoptotic events cannot be observed in the eggs maintaining high activity of MPF and CSF, and (iii) apoptosis in unfertilized frog eggs is accelerated upon early meiotic exit. The apoptotic features cannot be observed in the immature prophase-arrested oocytes, however, the maturation-inducing hormone progesterone renders oocytes susceptible to apoptosis. Conclusions The study reveals that naturally laid intact frog eggs die by apoptosis if they are not fertilized. A maternal apoptotic program is evoked in frog oocytes upon maturation and executed after meiotic exit in unfertilized eggs. The meiotic exit is required for execution of the apoptotic program in eggs. The emerging anti-apoptotic role of meiotic metaphase arrest needs further investigation. PMID:22195698

Donor Selection for Adult- to- Adult Living Donor Liver Transplantation: Well Begun is Half Done

PubMed Central

Sharma, Amit; Ashworth, April; Behnke, Martha; Cotterell, Adrian; Posner, Marc; Fisher, Robert A.

2012-01-01

Background Donor selection criteria for adult-to-adult living donor liver transplantation vary with the medical center of evaluation. Living donor evaluation utilizes considerable resources and the non-maturation of potential into actual donors may sometimes prove fatal for patients with end stage liver disease. On the contrary, a thorough donor evaluation process is mandatory to ensure safe outcomes in otherwise healthy donors. We aimed to study the reasons for non-maturation of potential right lobe liver donors at our transplant center. Methods A retrospective data analysis of all potential living liver donors evaluated at our center from 1998 to 2010 was done. Results Overall 324 donors were evaluated for 219 potential recipients and 171 (52.7%) donors were disqualified. Common reasons for donor non-maturation included: (1) Donor reluctance, 21% (2) >10% macro-vesicular steatosis, 16% (3) assisted donor withdrawal, 14% (4) inadequate remnant liver volume, 13% (5) psychosocial issues, 7% and thrombophilia, 7%. Ten donors (6%) were turned down due to anatomical variations (8 biliary and 2 arterial anomalies). Donors older than 50 years and those with BMI over 25 were less likely to be accepted for donation. Conclusions We conclude that donor reluctance, hepatic steatosis and assisted donor withdrawal are major reasons for non-maturation of potential into actual donors. Anatomical variations and underlying medical conditions were not a major cause of donor rejection. A system in practice to recognize these factors early in the course of donor evaluation to improve the efficiency of the selection process and ensure donor safety is proposed. PMID:23128999

Early Specialization in Youth Sport: A Biomechanical Perspective

ERIC Educational Resources Information Center

Mattson, Jeffrey M.; Richards, Jim

2010-01-01

This article examines, from a biomechanical perspective, three issues related to early specialization: overuse injuries, the developmental aspects, and the performance aspects. It concludes that "there is no evidence that early specialization causes overuse injuries or hinders growth and maturation." At the same time, early specialization has…

Effects of spring post-planting flooding on early soybean production systems in Mississippi

USDA-ARS?s Scientific Manuscript database

April planting of early-maturing soybean to avoid late-summer drought and to allow early harvest has become a common management practice in Mississippi. However, most of the early-planted soybeans on Sharkey clay soils in Mississippi are often exposed to waterlogged conditions during the early sprin...

When Friends' and Society's Expectations Collide: A Longitudinal Study of Moral Decision-Making and Personality across College.

PubMed

Bollich, Kathryn L; Hill, Patrick L; Harms, Peter D; Jackson, Joshua J

2016-01-01

Early adulthood is a developmentally important time period, with many novel life events needing to be traversed for the first time. Despite this important transition period, few studies examine the development of moral decision-making processes during this critical life stage. In the present study, college students completed moral decision-making measures during their freshman and senior years of college. Results indicate that, across four years, moral decision-making demonstrates considerable rank-order stability as well as change, such that people become more likely to help a friend relative to following societal rules. To help understand the mechanisms driving changes in moral decision-making processes, we examined their joint development with personality traits, a known correlate that changes during early adulthood in the direction of greater maturity. We found little evidence that personality and moral decision-making developmental processes are related. In sum, findings indicate that while moral decision-making processes are relatively stable across a four-year period, changes do occur which are likely independent of developmental processes driving personality trait change.

When Friends’ and Society’s Expectations Collide: A Longitudinal Study of Moral Decision-Making and Personality across College

PubMed Central

Bollich, Kathryn L.; Hill, Patrick L.; Harms, Peter D.; Jackson, Joshua J.

2016-01-01

Early adulthood is a developmentally important time period, with many novel life events needing to be traversed for the first time. Despite this important transition period, few studies examine the development of moral decision-making processes during this critical life stage. In the present study, college students completed moral decision-making measures during their freshman and senior years of college. Results indicate that, across four years, moral decision-making demonstrates considerable rank-order stability as well as change, such that people become more likely to help a friend relative to following societal rules. To help understand the mechanisms driving changes in moral decision-making processes, we examined their joint development with personality traits, a known correlate that changes during early adulthood in the direction of greater maturity. We found little evidence that personality and moral decision-making developmental processes are related. In sum, findings indicate that while moral decision-making processes are relatively stable across a four-year period, changes do occur which are likely independent of developmental processes driving personality trait change. PMID:26751944

Discrete β-adrenergic mechanisms regulate early and late erythropoiesis in erythropoietin-resistant anemia.

PubMed

Hasan, Shirin; Mosier, Michael J; Szilagyi, Andrea; Gamelli, Richard L; Muthumalaiappan, Kuzhali

2017-10-01

Anemia of critical illness is resistant to exogenous erythropoietin. Packed red blood cells transfusions is the only treatment option, and despite related cost and morbidity, there is a need for alternate strategies. Erythrocyte development can be divided into erythropoietin-dependent and erythropoietin-independent stages. We have shown previously that erythropoietin-dependent development is intact in burn patients and the erythropoietin-independent early commitment stage, which is regulated by β1/β2-adrenergic mechanisms, is compromised. Utilizing the scald burn injury model, we studied erythropoietin-independent late maturation stages and the effect of β1/β2, β-2, or β-3 blockade in burn mediated erythropoietin-resistant anemia. Burn mice were randomized to receive daily injections of propranolol (nonselective β1/β2 antagonist), nadolol (long-acting β1/β2 antagonist), butoxamine (selective β2 antagonist), or SR59230A (selective β3 antagonist) for 6 days after burn. Total bone marrow cells were characterized as nonerythroid cells, early and late erythroblasts, nucleated orthochromatic erythroblasts and enucleated reticulocyte subsets using CD71, Ter119, and Syto-16 by flow cytometry. Multipotential progenitors were probed for MafB expressing cells. Although propranolol improved early and late erythroblasts, only butoxamine and selective β3-antagonist administrations were positively reflected in the peripheral blood hemoglobin and red blood cells count. While burn impeded early commitment and late maturation stages, β1/β2 antagonism increased the early erythroblasts through commitment stages via β2 specific MafB regulation. β3 antagonism was more effective in improving overall red blood cells through late maturation stages. The study unfolds novel β2 and β3 adrenergic mechanisms orchestrating erythropoietin resistant anemia after burn, which impedes both the early commitment stage and the late maturation stages, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

Turf-type and early maturing annual ryegrass to establish perennial vegetation : technical report.

DOT National Transportation Integrated Search

2014-04-01

Annual ryegrass (Lolium multiflorum) is not currently recommended by TxDOT as a roadside re-vegetation nurse crop because its late maturity and height are too competitive for establishing perennial or spring plant mixtures. Two available genotypes us...

Structural and Maturational Covariance in Early Childhood Brain Development.

PubMed

Geng, Xiujuan; Li, Gang; Lu, Zhaohua; Gao, Wei; Wang, Li; Shen, Dinggang; Zhu, Hongtu; Gilmore, John H

2017-03-01

Brain structural covariance networks (SCNs) composed of regions with correlated variation are altered in neuropsychiatric disease and change with age. Little is known about the development of SCNs in early childhood, a period of rapid cortical growth. We investigated the development of structural and maturational covariance networks, including default, dorsal attention, primary visual and sensorimotor networks in a longitudinal population of 118 children after birth to 2 years old and compared them with intrinsic functional connectivity networks. We found that structural covariance of all networks exhibit strong correlations mostly limited to their seed regions. By Age 2, default and dorsal attention structural networks are much less distributed compared with their functional maps. The maturational covariance maps, however, revealed significant couplings in rates of change between distributed regions, which partially recapitulate their functional networks. The structural and maturational covariance of the primary visual and sensorimotor networks shows similar patterns to the corresponding functional networks. Results indicate that functional networks are in place prior to structural networks, that correlated structural patterns in adult may arise in part from coordinated cortical maturation, and that regional co-activation in functional networks may guide and refine the maturation of SCNs over childhood development. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Endometrial vessel maturation in women exposed to levonorgestrel-releasing intrauterine system for a short or prolonged period of time.

PubMed

Stéphanie, Ravet; Labied, Soraya; Blacher, Silvia; Frankenne, Francis; Munaut, Carine; Fridman, Viviana; Beliard, Aude; Foidart, Jean-Michel; Nisolle, Michelle

2007-12-01

Levonorgestrel-releasing intrauterine system (LNG-IUS), although inserted to reduce heavy menstruation, causes irregular early transient bleeding. The objective of the study was to document quantitative changes in endometrial vessels of short- (< or =3 months) and long-term (> or =12 months) LNG users. The area, density and maturation of endometrial vessels were quantified in 19 endometrial biopsies of women with LNG-IUS and in 10 normally ovulating patients during mid-luteal phase. Vessel maturation was evaluated by double immunostaining using anti-von Willebrand factor (endothelial cell marker) and anti-alpha Smooth Muscle Actin (vascular smooth muscle cells) antibodies. Vessel area, number and density were quantified with a novel computer-assisted image analysis system. Endometrium exposed to LNG-IUS for 1-3 months displayed a 11.5-fold increase in small naked vessel number. The partially mature vessel (alphaSMA partially positive) number increased six times. After long-term LNG-IUS treatment, the immature and partially mature vessel number remained four times higher than in the control group. Vessel area and density also increased dramatically in a time-dependent pattern with LNG-IUS use. Levonorgestrel affects blood vessel number, area, density and maturation in a time-dependent pattern that may explain the early transient increase in breakthrough bleeding with the LNG-IUS.

Early life vitamin D depletion alters the postnatal response to skeletal loading in growing and mature bone

PubMed Central

Buckley, Harriet; Owen, Robert; Marin, Ana Campos; Lu, Yongtau; Eyles, Darryl; Lacroix, Damien; Reilly, Gwendolen C.; Skerry, Tim M.; Bishop, Nick J.

2018-01-01

There is increasing evidence of persistent effects of early life vitamin D exposure on later skeletal health; linking low levels in early life to smaller bone size in childhood as well as increased fracture risk later in adulthood, independently of later vitamin D status. A major determinant of bone mass acquisition across all ages is mechanical loading. We tested the hypothesis in an animal model system that early life vitamin D depletion results in abrogation of the response to mechanical loading, with consequent reduction in bone size, mass and strength during both childhood and adulthood. A murine model was created in which pregnant dams were either vitamin D deficient or replete, and their offspring moved to a vitamin D replete diet at weaning. Tibias of the offspring were mechanically loaded and bone structure, extrinsic strength and growth measured both during growth and after skeletal maturity. Offspring of vitamin D deplete mice demonstrated lower bone mass in the non loaded limb and reduced bone mass accrual in response to loading in both the growing skeleton and after skeletal maturity. Early life vitamin D depletion led to reduced bone strength and altered bone biomechanical properties. These findings suggest early life vitamin D status may, in part, determine the propensity to osteoporosis and fracture that blights later life in many individuals. PMID:29370213

Developmental Changes in Organization of Structural Brain Networks

PubMed Central

Khundrakpam, Budhachandra S.; Reid, Andrew; Brauer, Jens; Carbonell, Felix; Lewis, John; Ameis, Stephanie; Karama, Sherif; Lee, Junki; Chen, Zhang; Das, Samir; Evans, Alan C.; Ball, William S.; Byars, Anna Weber; Schapiro, Mark; Bommer, Wendy; Carr, April; German, April; Dunn, Scott; Rivkin, Michael J.; Waber, Deborah; Mulkern, Robert; Vajapeyam, Sridhar; Chiverton, Abigail; Davis, Peter; Koo, Julie; Marmor, Jacki; Mrakotsky, Christine; Robertson, Richard; McAnulty, Gloria; Brandt, Michael E.; Fletcher, Jack M.; Kramer, Larry A.; Yang, Grace; McCormack, Cara; Hebert, Kathleen M.; Volero, Hilda; Botteron, Kelly; McKinstry, Robert C.; Warren, William; Nishino, Tomoyuki; Robert Almli, C.; Todd, Richard; Constantino, John; McCracken, James T.; Levitt, Jennifer; Alger, Jeffrey; O'Neil, Joseph; Toga, Arthur; Asarnow, Robert; Fadale, David; Heinichen, Laura; Ireland, Cedric; Wang, Dah-Jyuu; Moss, Edward; Zimmerman, Robert A.; Bintliff, Brooke; Bradford, Ruth; Newman, Janice; Evans, Alan C.; Arnaoutelis, Rozalia; Bruce Pike, G.; Louis Collins, D.; Leonard, Gabriel; Paus, Tomas; Zijdenbos, Alex; Das, Samir; Fonov, Vladimir; Fu, Luke; Harlap, Jonathan; Leppert, Ilana; Milovan, Denise; Vins, Dario; Zeffiro, Thomas; Van Meter, John; Lange, Nicholas; Froimowitz, Michael P.; Botteron, Kelly; Robert Almli, C.; Rainey, Cheryl; Henderson, Stan; Nishino, Tomoyuki; Warren, William; Edwards, Jennifer L.; Dubois, Diane; Smith, Karla; Singer, Tish; Wilber, Aaron A.; Pierpaoli, Carlo; Basser, Peter J.; Chang, Lin-Ching; Koay, Chen Guan; Walker, Lindsay; Freund, Lisa; Rumsey, Judith; Baskir, Lauren; Stanford, Laurence; Sirocco, Karen; Gwinn-Hardy, Katrina; Spinella, Giovanna; McCracken, James T.; Alger, Jeffry R.; Levitt, Jennifer; O'Neill, Joseph

2013-01-01

Recent findings from developmental neuroimaging studies suggest that the enhancement of cognitive processes during development may be the result of a fine-tuning of the structural and functional organization of brain with maturation. However, the details regarding the developmental trajectory of large-scale structural brain networks are not yet understood. Here, we used graph theory to examine developmental changes in the organization of structural brain networks in 203 normally growing children and adolescents. Structural brain networks were constructed using interregional correlations in cortical thickness for 4 age groups (early childhood: 4.8–8.4 year; late childhood: 8.5–11.3 year; early adolescence: 11.4–14.7 year; late adolescence: 14.8–18.3 year). Late childhood showed prominent changes in topological properties, specifically a significant reduction in local efficiency, modularity, and increased global efficiency, suggesting a shift of topological organization toward a more random configuration. An increase in number and span of distribution of connector hubs was found in this age group. Finally, inter-regional connectivity analysis and graph-theoretic measures indicated early maturation of primary sensorimotor regions and protracted development of higher order association and paralimbic regions. Our finding reveals a time window of plasticity occurring during late childhood which may accommodate crucial changes during puberty and the new developmental tasks that an adolescent faces. PMID:22784607

Preclinical Immunomodulation by the Probiotic Bifidobacterium breve M-16V in Early Life

PubMed Central

Rigo-Adrover, Maria del Mar; Franch, Àngels; Castell, Margarida; Pérez-Cano, Francisco José

2016-01-01

This study aimed to investigate the effect of supplementation with the probiotic Bifidobacterium breve M-16V on the maturation of the intestinal and circulating immune system during suckling. In order to achieve this purpose, neonatal Lewis rats were supplemented with the probiotic strain from the 6th to the 18th day of life. The animals were weighed during the study, and faecal samples were obtained and evaluated daily. On day 19, rats were euthanized and intestinal wash samples, mesenteric lymph node (MLN) cells, splenocytes and intraepithelial lymphocytes (IEL) were obtained. The probiotic supplementation in early life did not modify the growth curve and did not enhance the systemic immune maturation. However, it increased the proportion of cells bearing TLR4 in the MLN and IEL, and enhanced the percentage of the integrin αEβ7+ and CD62L+ cells in the MLN and that of the integrin αEβ7+ cells in the IEL, suggesting an enhancement of the homing process of naïve T lymphocytes to the MLN, and the retention of activated lymphocytes in the intraepithelial compartment. Interestingly, B. breve M-16V enhanced the intestinal IgA synthesis. In conclusion, supplementation with the probiotic strain B. breve M-16V during suckling improves the development of mucosal immunity in early life. PMID:27820846

Evaluation of microbial diversity in the pilot-scale beer brewing process by culture-dependent and culture-independent method.

PubMed

Takahashi, M; Kita, Y; Kusaka, K; Mizuno, A; Goto-Yamamoto, N

2015-02-01

In the brewing industry, microbial management is very important for stabilizing the quality of the product. We investigated the detailed microbial community of beer during fermentation and maturation, to manage beer microbiology in more detail. We brewed a beer (all-malt) and two beerlike beverages (half- and low-malt) in pilot-scale fermentation and investigated the microbial community of them using a next-generation sequencer (454 GS FLX titanium), quantitative PCR, flow cytometry and a culture-dependent method. From 28 to 88 genera of bacteria and from 9 to 38 genera of eukaryotic micro-organisms were detected in each sample. Almost all micro-organisms died out during the boiling process. However, bacteria belonging to the genera Acidovorax, Bacillus, Brevundimonas, Caulobacter, Chryseobacterium, Methylobacterium, Paenibacillus, Polaromonas, Pseudomonas, Ralstonia, Sphingomonas, Stenotrophomonas, Tepidimonas and Tissierella were detected at the early and middle stage of fermentation, even though their cell densities were low (below approx. 10(3) cells ml(-1) ) and they were not almost detected at the end of fermentation. We revealed that the microbial community of beer during fermentation and maturation is very diverse and several bacteria possibly survive during fermentation. In this study, we revealed the detailed microbial communities of beer using next-generation sequencing. Some of the micro-organisms detected in this study were found in beer brewing process for the first time. Additionally, the possibility of growth of several bacteria at the early and middle stage of fermentation was suggested. © 2014 The Society for Applied Microbiology.

Seasonal reproductive development of Lampsilis cardium, Amblema plicata plicata, and Potamilus alatus

USGS Publications Warehouse

Holland Bartels, L. E.; Kammer, T.W.

1989-01-01

Adult specimens of three species of freshwater mussels common to the upper Mississippi River were examined histologically to determine seasonal patterns of development in gametogenesis and release of glochidia. Full maturation of gonadal materials in Lampsilis cardium (formerly L. ovata ventricosa), a long-term breeder, occurred when ambient river temperatures reached 24 degree to 26 degree C, between late July and early August. By mid-August, glochidia were present in the marsupia. Glochidia were released from late May through mid-June of the following year once water temperatures reached 20 degree C. The long-term breeder Potamilus alatus demonstrated full gonadal maturation earlier than seen in L. cardium with reproduction completed by late July (26 degree C). Glochidia of P. alatus were released over a period similar to that observed for L. cardium, late May through early July of the following year. Fully mature Amblema plicata plicata, a short-term breeder, were collected from late May through early July (18 degree to 21 degree C). (DBO).

Seasonal Reproductive Biology of Drosophila suzukii (Diptera: Drosophilidae) in Temperate Climates.

PubMed

Grassi, Alberto; Gottardello, Angela; Dalton, Daniel T; Tait, Gabriella; Rendon, Dalila; Ioriatti, Claudio; Gibeaut, David; Rossi Stacconi, M Valerio; Walton, Vaughn M

2018-02-08

Drosophila suzukii (Matsumura; Diptera: Drosophilidae) is a key pest of sweet cherry and small fruits worldwide. The present studies were designed to describe the reproductive physiology in both sexes, through dissections of their reproductive organs. We extensively dissected female D. suzukii throughout the season from 2013 to 2016 and classified the reproductive status flies based on five recognizable ovarian maturation stages: 1) no ovaries; 2) unripe ovaries 3) ripening eggs in ovarioles; 4) mature eggs in ovarioles; and 5) mature eggs in the abdomen. Development was examined as a function of calendar days as well as degree-days (DD). Results obtained from winter collections revealed that females collected from November to March contained a lower percentage of mature eggs than females collected from April to September. These data suggest that environmental conditions during the dormant period induce reproductive diapause. Oogenesis likely increased with an increase in mean monthly temperatures and DD. The first overwintered females with mature eggs were dissected as early as 21 February 2014 in Trento (7 DD). Additionally, we found that a low proportion of males (less than 50%) had sperm in their testes between January and March, yet during the same period females already have sperm stored in their spermathecal. Ivy berries was an alternative but unfavorable non-crop host during the late dormant period, as evidenced by emergence of smaller adults when compared to individuals emerging from cherry fruits. This study showed that D. suzukii females have great potential for oviposition early in the season, posing a risk to early season maturing crop hosts. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Executive functioning before and after onset of alcohol use disorder in adolescence. A TRAILS study.

PubMed

Boelema, Sarai R; Harakeh, Zeena; van Zandvoort, Martine J E; Reijneveld, Sijmen A; Verhulst, Frank C; Ormel, Johan; Vollebergh, Wilma A M

2016-07-01

The aim of the present study was to investigate whether executive functioning (EF) in early adolescence predicted alcohol use disorder (AUD) in late adolescence and whether adolescents with AUD differed in maturation of EF from controls without a diagnosis. We used the data from the Tracking Adolescents' Individual Lives Survey (TRAILS), a cohort of 2230 Dutch adolescents. Working memory, inhibition, and attention were measured at ages 11 and 19. At age 19, lifetime DSM-IV diagnoses were determined, resulting in a control group (n = 1111) and two AUD groups, i.e., alcohol abusers (n = 381) and alcohol dependents (n = 51). Regression analyses assessed whether EF at age 11 predicted the transition to AUD in late adolescence and whether AUD affected maturation of EF from age 11 to 19. EF in early adolescence did not predict AUD in late adolescence. A significant interaction effect emerged between gender and alcohol dependence for shift attention (β = 0.12, SE=0.36), with girls showing smaller maturational rates. This effect remained significant after controlling for alcohol intake (ages 16 and 19) and comorbid psychiatric disorders. Our results do not replicate the finding that EF in early adolescence is a significant predictor of AUD in late adolescence. Furthermore, for the majority of tasks, adolescents with AUD do not differ in EF maturation over the course of adolescence. Alcohol dependent girls however, show less maturation of shift attention. This is independent of the quantity of alcohol intake, which could suggest that non-normative maturation of EF is associated with the behavioural components of AUD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sociality and individual fitness in yellow-bellied marmots: insights from a long-term study (1962-2001).

PubMed

Oli, Madan K; Armitage, Kenneth B

2003-08-01

Theoretical and empirical studies suggest that the age of first reproduction (the age at which reproduction begins) can have a substantial influence on population dynamics and individual fitness. Using complete survival and reproductive histories of 428 female yellow-bellied marmots (Marmota flaviventris) from a 40-year study (1962-2001), we investigated causes and fitness consequences of delayed maturity. Most females (86%) died without reproducing. The age of first reproduction of females that survived to reproduce at least once (n=60) ranged from 2 to 6 years. Females maturing later did not have a larger lifetime number of successful reproductive events or offspring production, nor did they experience improved survival. Females reproducing earlier had a higher fitness than those that delayed maturity. These results suggest that the net cost of early maturity was less than fitness benefits associated with early onset of reproduction, and that age of first reproduction in our study population is under substantial directional selection favoring early maturity. We conclude that female yellow-bellied marmots delay onset of reproduction not because of fitness benefits of foregoing reproduction at an earlier age, but due to the social suppression of reproduction by older, reproductive females, which enhances their own fitness to the detriment of the fitness of young females. Our results indicate that female yellow-bellied marmots that survive to reproduce may act to increase their own direct fitness, and that social suppression of reproduction of young females is a part of that strategy.

Age at menarche, reactions to menarche and attitudes towards menstruation among Mexican adolescent girls.

PubMed

Marván, Ma Luisa; Alcalá-Herrera, Verónica

2014-04-01

To investigate the relationships between menarcheal timing and both menarcheal experience and attitudes toward menstruation in Mexican girls. Cross-sectional survey. Sample of adolescents attending 10 different public schools. Mexican postmenarcheal adolescents, aged 11-16 years. Participants answered 1 questionnaire about menarcheal experience and another about attitudes towards menstruation. Early maturers (menarche before 11 years) were more likely than average (menarche at 11 or 12 years) or late maturers (menarche at 13 or more years) to state they had not known what they should do at the moment they got their first period (P < .01), that they had not felt prepared to start menstruating (P < .05), and that they thought they must keep secret the fact of already having had their first period (P < .05). Concerning their emotional reactions to menarche, early maturers were the most likely to have felt scared (P < .05), worried (P < .05) and sad (P < .05) and were the least likely to have felt calm (P < .05). They were also the most likely to show current secretive attitudes towards menstruation (P < .01). Finally, late maturers showed more positive attitudes toward menstruation than their peers (P < .01). These results could be useful for developing resources to help early maturing girls manage menstruation. Since these girls have limited or in some cases no time for preparation, they need special support. Copyright © 2014 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Rodent Zic Genes in Neural Network Wiring.

PubMed

Herrera, Eloísa

2018-01-01

The formation of the nervous system is a multistep process that yields a mature brain. Failure in any of the steps of this process may cause brain malfunction. In the early stages of embryonic development, neural progenitors quickly proliferate and then, at a specific moment, differentiate into neurons or glia. Once they become postmitotic neurons, they migrate to their final destinations and begin to extend their axons to connect with other neurons, sometimes located in quite distant regions, to establish different neural circuits. During the last decade, it has become evident that Zic genes, in addition to playing important roles in early development (e.g., gastrulation and neural tube closure), are involved in different processes of late brain development, such as neuronal migration, axon guidance, and refinement of axon terminals. ZIC proteins are therefore essential for the proper wiring and connectivity of the brain. In this chapter, we review our current knowledge of the role of Zic genes in the late stages of neural circuit formation.

Nanoscale assembly processes revealed in the nacroprismatic transition zone of Pinna nobilis mollusc shells

PubMed Central

Hovden, Robert; Wolf, Stephan E.; Holtz, Megan E.; Marin, Frédéric; Muller, David A.; Estroff, Lara A.

2015-01-01

Intricate biomineralization processes in molluscs engineer hierarchical structures with meso-, nano- and atomic architectures that give the final composite material exceptional mechanical strength and optical iridescence on the macroscale. This multiscale biological assembly inspires new synthetic routes to complex materials. Our investigation of the prism–nacre interface reveals nanoscale details governing the onset of nacre formation using high-resolution scanning transmission electron microscopy. A wedge-polishing technique provides unprecedented, large-area specimens required to span the entire interface. Within this region, we find a transition from nanofibrillar aggregation to irregular early-nacre layers, to well-ordered mature nacre suggesting the assembly process is driven by aggregation of nanoparticles (∼50–80 nm) within an organic matrix that arrange in fibre-like polycrystalline configurations. The particle number increases successively and, when critical packing is reached, they merge into early-nacre platelets. These results give new insights into nacre formation and particle-accretion mechanisms that may be common to many calcareous biominerals. PMID:26631940

[The effect of bemithyl on the onthogenesis of rats].

PubMed

Spasov, A A; Bugaeva, L I; Denisova, T D; Smirnova, L A

2005-01-01

Female rats were treated with bemithyl (20 and 100 mg/kg) via a gastric tube during a 16-day period of lactation. It was found that the drug is transferred with breast milk to the organism of newborns, which leads to nonuniformities in their development. Among the early effects of bemithyl, most pronounced is the stimulating action upon maturation (muscle strength) and the development of sensor-locomotor reflexes; in the spectrum of long-term effects, the drug influence upon pubescence processes was manifested.

[Nonprocess autism in children: comparative etiopathogenetic study].

PubMed

Kagan, V E

1979-01-01

Etiopathogenesis of the childhood autism syndrome of a non-process nature is discussed on the basis of a comparative study of 156 children aged from 3 to 16 years. In the etiological complex there is a prevalence of early exogenous-organic noxious factors, which is reflected in disturbances of mental divelopment, maturation of the system of hemispheric pair work. The data of follow-up studies and treatment confirm a conclusion about a residual-organic basis in the syndrome of childhood autism.

Methods for evaluating a mature substance abuse prevention/early intervention program.

PubMed

Becker, L R; Hall, M; Fisher, D A; Miller, T R

2000-05-01

The authors describe methods for work in progress to evaluate four workplace prevention and/or early intervention programs designed to change occupational norms and reduce substance abuse at a major U.S. transportation company. The four programs are an employee assistance program, random drug testing, managed behavioral health care, and a peer-led intervention program. An elaborate mixed-methods evaluation combines data collection and analysis techniques from several traditions. A process-improvement evaluation focuses on the peer-led component to describe its evolution, document the implementation process for those interested in replicating it, and provide information for program improvement. An outcome-assessment evaluation examines impacts of the four programs on job performance measures (e.g., absenteeism, turnover, injury, and disability rates) and includes a cost-offset and employer cost-savings analysis. Issues related to using archival data, combining qualitative and quantitative designs, and working in a corporate environment are discussed.

The impact of canopy managements on grape and wine composition of cv. 'Istrian Malvasia' (Vitis vinifera L.).

PubMed

Rescic, Jan; Mikulic-Petkovsek, Maja; Rusjan, Denis

2016-11-01

The interest in producing wines preferred by consumers increases the need for improving practices to modify grape and wine composition. The aim of this study was to assess the impacts of three different canopy management measures, (1) early leaf removal in the cluster zone, (2) removal of young leaves above the second pair of wires and (3) Double Maturation Raisonnée, on the yield and chemical composition of 'Istrian Malvasia' grape and wine. Double Maturation Raisonnée had a significantly greater impact on phenolic compounds, while the highest soluble solids (24.3 and 23.5 °Brix) and titratable acidity (7.0 and 7.1 g L -1 ) were measured at early leaf removal. Leaf removal at véraison caused an unexpected augmentation of flavonols in the berry skin. Early leaf removal resulted in significantly lower extracts of wine. Nevertheless, they reached the highest mark (16.5 out of 20.0 points) in sensory evaluation compared with leaf removal at véraison and Double Maturation Raisonnée (15.0 points) and control (16.0 points). Leaf removal at véraison and Double Maturation Raisonnée improved the phenolic composition of wine, producing a full-bodied wine. On the other hand, early leaf removal significantly augmented the yield and titratable acidity, hydroxycinnamic acids and flavanols of wine, which might have led to a fresher but less-bodied wine. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

The Adjuvant LT-K63 Can Restore Delayed Maturation of Follicular Dendritic Cells and Poor Persistence of Both Protein- and Polysaccharide-Specific Antibody-Secreting Cells in Neonatal Mice

PubMed Central

Bjarnarson, Stefania P.; Adarna, Brenda C.; Benonisson, Hreinn; Del Giudice, Giuseppe

2012-01-01

Ab responses in early life are low and short-lived; therefore, induction of protective immunity requires repeated vaccinations. One of the major limitations in early-life immunity is delayed maturation of follicular dendritic cells (FDCs), which play a central role in mediating the germinal center (GC) reaction leading to production of Ab-secreting cells (AbSCs). We assessed whether a nontoxic mutant of Escherichia coli heat-labile enterotoxin (LT-K63) and CpG1826 as model adjuvants could accelerate FDC maturation and immune response in neonatal mice, using a pneumococcal polysaccharide of serotype 1 conjugated to tetanus toxoid (Pnc1-TT) as a model vaccine. In neonatal NMRI mice, a single dose of Pnc1-TT coadministered with LT-K63 enhanced Pnc1-TT–induced GC reaction. In contrast, CpG1826 had no effect. Accordingly, LT-K63, but not CpG1826, accelerated the maturation of FDC networks, detected by FDC-M2+ staining, characteristic for adult-like FDCs. This coincided with migration of MOMA-1+ macrophages into the GCs that can enhance GC reaction and B cell activation. The FDC-M2+ FDC networks colocalized with enhanced expression of TNF-α, which is critical for the maintenance of mature FDCs and is poorly expressed in neonates. The accelerated maturation of FDC networks correlated with increased frequency and prolonged persistence of polysaccharide- and protein-specific IgG+ AbSCs in spleen and bone marrow. Our data show for the first time, to our knowledge, that an adjuvant (LT-K63) can overcome delayed maturation of FDCs in neonates, enhance the GC reaction, and prolong the persistence of vaccine-specific AbSCs in the BM. These properties are attractive for parenteral vaccination in early life. PMID:22753937

Decreased phosphorylation of δ and ε subunits of the acetylcholine receptor coincides with delayed postsynaptic maturation in PKC θ deficient mouse.

PubMed

Lanuza, Maria A; Besalduch, Núria; González, Carmen; Santafé, Manel M; Garcia, Neus; Tomàs, Marta; Nelson, Phillip G; Tomàs, Josep

2010-09-01

Protein kinase C (PKC) activity is involved in the nicotinic acetylcholine receptor (nAChR) redistribution at the neuromuscular junction in vivo during postnatal maturation. Here we studied, in PKC theta (PKCtheta) deficient mice (KO), how the theta isoform of PKC is involved in the nAChR cluster maturation that is accompanied by the developmental activity-dependent neuromuscular synapse elimination process. We found that axonal elimination and dispersion of nAChR from the postsynaptic plaques and its redistribution to form the mature postsynaptic apparatus were delayed but not totally suppressed in PKCtheta deficient mice. Moreover, the delay in the maturation of the morphology of the nAChR clusters during the early postnatal synapse elimination period in the PKCtheta deficient mice coincides with a reduction in the PKCtheta-mediated phosphorylation on the delta subunit of the nAChR. In addition, we show evidence for PKCtheta regulation of PKA in normally phosphorylating the epsilon subunit of nAChR. We have also found that the theta isoform of PKC is located on the postsynaptic component of the neuromuscular junction but is also expressed by motoneurons in the spinal cord and in the motor nerve terminals. The results allow us to hypothesize that a spatially specific and opposing action of PKCtheta and PKA may result in activity-dependent alterations to synaptic connectivity at both the nerve inputs and the postsynaptic nAChR clusters. Copyright 2010 Elsevier Inc. All rights reserved.

Early-life nutritional effects on the female reproductive system.

PubMed

Chan, K A; Tsoulis, M W; Sloboda, D M

2015-02-01

There is now considerable epidemiological and experimental evidence indicating that early-life environmental conditions, including nutrition, affect subsequent development in later life. These conditions induce highly integrated responses in endocrine-related homeostasis, resulting in persistent changes in the developmental trajectory producing an altered adult phenotype. Early-life events trigger processes that prepare the individual for particular circumstances that are anticipated in the postnatal environment. However, where the intrauterine and postnatal environments differ markedly, such modifications to the developmental trajectory may prove maladaptive in later life. Reproductive maturation and function are similarly influenced by early-life events. This should not be surprising, because the primordial follicle pool is established early in life and is thus vulnerable to early-life events. Results of clinical and experimental studies have indicated that early-life adversity is associated with a decline in ovarian follicular reserve, changes in ovulation rates, and altered age at onset of puberty. However, the underlying mechanisms regulating the relationship between the early-life developmental environment and postnatal reproductive development and function are unclear. This review examines the evidence linking early-life nutrition and effects on the female reproductive system, bringing together clinical observations in humans and experimental data from targeted animal models. © 2015 Society for Endocrinology.

From stem cell to embryo without centrioles.

PubMed

Stevens, Naomi R; Raposo, Alexandre A S F; Basto, Renata; St Johnston, Daniel; Raff, Jordan W

2007-09-04

Centrosome asymmetry plays a key role in ensuring the asymmetric division of Drosophila neural stem cells (neuroblasts [NBs]) and male germline stem cells (GSCs) [1-3]. In both cases, one centrosome is anchored close to a specific cortical region during interphase, thus defining the orientation of the spindle during the ensuing mitosis. To test whether asymmetric centrosome behavior is a general feature of stem cells, we have studied female GSCs, which divide asymmetrically, producing another GSC and a cystoblast. The cystoblast then divides and matures into an oocyte, a process in which centrosomes exhibit a series of complex behaviors proposed to play a crucial role in oogenesis [4-6]. We show that the interphase centrosome does not define spindle orientation in female GSCs and that DSas-4 mutant GSCs [7], lacking centrioles and centrosomes, invariably divide asymmetrically to produce cystoblasts that proceed normally through oogenesis-remarkably, oocyte specification, microtubule organization, and mRNA localization are all unperturbed. Mature oocytes can be fertilized, but embryos that cannot support centriole replication arrest very early in development. Thus, centrosomes are dispensable for oogenesis but essential for early embryogenesis. These results reveal that asymmetric centrosome behavior is not an essential feature of stem cell divisions.

Cyclin B in mouse oocytes and embryos: importance for human reproduction and aneuploidy.

PubMed

Polański, Zbigniew; Homer, Hayden; Kubiak, Jacek Z

2012-01-01

Oocyte maturation and early embryo development require precise coordination between cell cycle progression and the developmental programme. Cyclin B plays a major role in this process: its accumulation and degradation is critical for driving the cell cycle through activation and inactivation of the major cell cycle kinase, CDK1. CDK1 activation is required for M-phase entry whereas its inactivation leads to exit from M-phase. The tempo of oocyte meiotic and embryonic mitotic divisions is set by the rate of cyclin B accumulation and the timing of its destruction. By controlling when cyclin B destruction is triggered and by co-ordinating this with the completion of chromosome alignment, the spindle assembly checkpoint (SAC) is a critical quality control system important for averting aneuploidy and for building in the flexibility required to better integrate cell cycle progression with development. In this review we focus on cyclin B metabolism in mouse oocytes and embryos and illustrate how the cell cycle-powered clock (in fact cyclin B-powered clock) controls oocyte maturation and early embryo development, thereby providing important insight into human reproduction and potential causes of Down syndrome.

Modified Maturity Offset Prediction Equations: Validation in Independent Longitudinal Samples of Boys and Girls.

PubMed

Kozieł, Sławomir M; Malina, Robert M

2018-01-01

Predicted maturity offset and age at peak height velocity are increasingly used with youth athletes, although validation studies of the equations indicated major limitations. The equations have since been modified and simplified. The objective of this study was to validate the new maturity offset prediction equations in independent longitudinal samples of boys and girls. Two new equations for boys with chronological age and sitting height and chronological age and stature as predictors, and one equation for girls with chronological age and stature as predictors were evaluated in serial data from the Wrocław Growth Study, 193 boys (aged 8-18 years) and 198 girls (aged 8-16 years). Observed age at peak height velocity for each youth was estimated with the Preece-Baines Model 1. The original prediction equations were included for comparison. Predicted age at peak height velocity was the difference between chronological age at prediction and maturity offset. Predicted ages at peak height velocity with the new equations approximated observed ages at peak height velocity in average maturing boys near the time of peak height velocity; a corresponding window for average maturing girls was not apparent. Compared with observed age at peak height velocity, predicted ages at peak height velocity with the new and original equations were consistently later in early maturing youth and earlier in late maturing youth of both sexes. Predicted ages at peak height velocity with the new equations had reduced variation compared with the original equations and especially observed ages at peak height velocity. Intra-individual variation in predicted ages at peak height velocity with all equations was considerable. The new equations are useful for average maturing boys close to the time of peak height velocity; there does not appear to be a clear window for average maturing girls. The new and original equations have major limitations with early and late maturing boys and girls.

The evolution of pollen germination timing in flowering plants: Austrobaileya scandens (Austrobaileyaceae)

PubMed Central

Williams, Joseph H.

2012-01-01

Background and aims The pollination to fertilization process (progamic phase) is thought to have become greatly abbreviated with the origin of flowering plants. In order to understand what developmental mechanisms enabled the speeding of fertilization, comparative data are needed from across the group, especially from early-divergent lineages. I studied the pollen germination process of Austrobaileya scandens, a perennial vine endemic to the Wet Tropics area of northeastern Queensland, Australia, and a member of the ancient angiosperm lineage, Austrobaileyales. Methodology I used in vivo and in vitro hand pollinations and timed collections to study development from late pollen maturation to just after germination. Then I compared the contribution of pollen germination timing to progamic phase duration in 131 angiosperm species (65 families). Principal findings Mature pollen of Austrobaileya was bicellular, starchless and moderately dehydrated—water content was 31.5 % by weight and volume increased by 57.9 % upon hydration. A callose layer in the inner intine appeared only after pollination. In vivo pollen germination followed a logarithmic curve, rising from 28 % at 1 hour after pollination (hap) to 97 % at 12 hap (R2 = 0.98). Sufficient pollen germination to fertilize all ovules was predicted to have occurred within 62 min. Across angiosperms, pollen germination ranged from 1 min to >60 h long and required 8.3 ± 9.8 % of the total duration of the progamic phase. Significance Pollen of Austrobaileya has many plesiomorphic features that are thought to prolong germination. Yet its germination is quite fast for species with desiccation-tolerant pollen (range: <1 to 60 h). Austrobaileya and other early-divergent angiosperms have relatively rapid pollen germination and short progamic phases, comparable to those of many insect-pollinated monocots and eudicots. These results suggest that both the pollen germination and pollen tube growth periods were marked by acceleration of developmental processes early in angiosperm history. PMID:22567221

The evolution of pollen germination timing in flowering plants: Austrobaileya scandens (Austrobaileyaceae).

PubMed

Williams, Joseph H

2012-01-01

The pollination to fertilization process (progamic phase) is thought to have become greatly abbreviated with the origin of flowering plants. In order to understand what developmental mechanisms enabled the speeding of fertilization, comparative data are needed from across the group, especially from early-divergent lineages. I studied the pollen germination process of Austrobaileya scandens, a perennial vine endemic to the Wet Tropics area of northeastern Queensland, Australia, and a member of the ancient angiosperm lineage, Austrobaileyales. I used in vivo and in vitro hand pollinations and timed collections to study development from late pollen maturation to just after germination. Then I compared the contribution of pollen germination timing to progamic phase duration in 131 angiosperm species (65 families). Mature pollen of Austrobaileya was bicellular, starchless and moderately dehydrated-water content was 31.5 % by weight and volume increased by 57.9 % upon hydration. A callose layer in the inner intine appeared only after pollination. In vivo pollen germination followed a logarithmic curve, rising from 28 % at 1 hour after pollination (hap) to 97 % at 12 hap (R(2) = 0.98). Sufficient pollen germination to fertilize all ovules was predicted to have occurred within 62 min. Across angiosperms, pollen germination ranged from 1 min to >60 h long and required 8.3 ± 9.8 % of the total duration of the progamic phase. Pollen of Austrobaileya has many plesiomorphic features that are thought to prolong germination. Yet its germination is quite fast for species with desiccation-tolerant pollen (range: <1 to 60 h). Austrobaileya and other early-divergent angiosperms have relatively rapid pollen germination and short progamic phases, comparable to those of many insect-pollinated monocots and eudicots. These results suggest that both the pollen germination and pollen tube growth periods were marked by acceleration of developmental processes early in angiosperm history.

Neural competition as a developmental process: Early hemispheric specialization for word processing delays specialization for face processing

PubMed Central

Li, Su; Lee, Kang; Zhao, Jing; Yang, Zhi; He, Sheng; Weng, Xuchu

2013-01-01

Little is known about the impact of learning to read on early neural development for word processing and its collateral effects on neural development in non-word domains. Here, we examined the effect of early exposure to reading on neural responses to both word and face processing in preschool children with the use of the Event Related Potential (ERP) methodology. We specifically linked children’s reading experience (indexed by their sight vocabulary) to two major neural markers: the amplitude differences between the left and right N170 on the bilateral posterior scalp sites and the hemispheric spectrum power differences in the γ band on the same scalp sites. The results showed that the left-lateralization of both the word N170 and the spectrum power in the γ band were significantly positively related to vocabulary. In contrast, vocabulary and the word left-lateralization both had a strong negative direct effect on the face right-lateralization. Also, vocabulary negatively correlated with the right-lateralized face spectrum power in the γ band even after the effects of age and the word spectrum power were partialled out. The present study provides direct evidence regarding the role of reading experience in the neural specialization of word and face processing above and beyond the effect of maturation. The present findings taken together suggest that the neural development of visual word processing competes with that of face processing before the process of neural specialization has been consolidated. PMID:23462239

Representational constraints on the development of memory and metamemory: a developmental-representational theory.

PubMed

Ceci, Stephen J; Fitneva, Stanka A; Williams, Wendy M

2010-04-01

Traditional accounts of memory development suggest that maturation of prefrontal cortex (PFC) enables efficient metamemory, which enhances memory. An alternative theory is described, in which changes in early memory and metamemory are mediated by representational changes, independent of PFC maturation. In a pilot study and Experiment 1, younger children failed to recognize previously presented pictures, yet the children could identify the context in which they occurred, suggesting these failures resulted from inefficient metamemory. Older children seldom exhibited such failure. Experiment 2 established that this was not due to retrieval-time recoding. Experiment 3 suggested that young children's representation of a picture's attributes explained their metamemory failure. Experiment 4 demonstrated that metamemory is age-invariant when representational quality is controlled: When stimuli were equivalently represented, age differences in memory and metamemory declined. These findings do not support the traditional view that as children develop, neural maturation permits more efficient monitoring, which leads to improved memory. These findings support a theory based on developmental-representational synthesis, in which constraints on metamemory are independent of neurological development; representational features drive early memory to a greater extent than previously acknowledged, suggesting that neural maturation has been overimputed as a source of early metamemory and memory failure. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Pubertal timing and early sexual intercourse in the offspring of teenage mothers.

PubMed

De Genna, Natacha M; Larkby, Cynthia; Cornelius, Marie D

2011-10-01

Early puberty is associated with stressful family environments, early sexual intercourse, and teenage pregnancy. We examined pubertal timing and sexual debut among the 14-year-old offspring of teenage mothers. Mothers (71% Black, 29% White) were recruited as pregnant teenagers (12-18 years old). Data were collected during pregnancy and when offspring were 6, 10 and 14 years old (n = 318). Adolescents (50% male) compared the timing of their pubertal maturation to same-sex peers. There was a significant 3-way interaction effect of race, sex, and pubertal timing on sexual debut (n = 305). This effect remained significant in a model controlling for maternal age at first intercourse, substance use, exposure to trauma, authoritative parenting, and peer sexual activity (n = 255). Early maturation was associated with early sex in daughters, and may be one pathway for the inter-generational transfer of risk for teenage pregnancy among daughters of teenage mothers.

Pubertal Timing and Early Sexual Intercourse in the Offspring of Teenage Mothers

PubMed Central

De Genna, Natacha M.; Larkby, Cynthia; Cornelius, Marie D.

2011-01-01

Early puberty is associated with stressful family environments, early sexual intercourse, and teenage pregnancy. We examined pubertal timing and sexual debut among the 14-year-old offspring of teenage mothers. Mothers (71% Black, 29% White) were recruited as pregnant teenagers (12–18 years old). Data were collected during pregnancy and when offspring were 6, 10 and 14 years old (n = 318). Adolescents (50% male) compared the timing of their pubertal maturation to same-sex peers. There was a significant 3-way interaction effect of race, sex, and pubertal timing on sexual debut (n = 305). This effect remained significant in a model controlling for maternal age at first intercourse, substance use, exposure to trauma, authoritative parenting, and peer sexual activity (n = 255). Early maturation was associated with early sex in daughters, and may be one pathway for the inter-generational transfer of risk for teenage pregnancy among daughters of teenage mothers. PMID:21279428

HYDROCARBON SOURCE ROCK EVALUATION OF MIDDLE PROTEROZOIC SOLOR CHURCH FORMATION, NORTH AMERICAN MID-CONTINENT RIFT SYSTEM, RICE COUNTY, MINNESOTA.

USGS Publications Warehouse

Hatch, J.R.; Morey, G.B.

1985-01-01

Hydrocarbon source rock evaluation of the Middle Proterozoic Solor Church Formation (Keweenawan Supergroup) as sampled in the Lonsdale 65-1 well, Rice County, shows that: the rocks are organic matter lean; the organic matter is thermally post-mature, probably near the transition between the wet gas phase of catagenesis and metagenesis; and the rocks have minimal potential for producing additional hydrocarbons. The observed thermal maturity of the organic matter requires significantly greater burial depths, a higher geothermal gradient, or both. It is likely, that thermal maturation of the organic matter in the Solor Church took place relatively early, and that any hydrocarbons generated during this early phase were probably lost prior to deposition of the overlying formation.

Relation of adrenal-derived steroids with bone maturation, mineral density and geometry in healthy prepubertal and early pubertal boys.

PubMed

Vandewalle, S; Taes, Y; Fiers, T; Toye, K; Van Caenegem, E; Kaufman, J-M; De Schepper, J

2014-12-01

Little is known about the effects of adrenal steroids on skeletal maturation and bone mass acquisition in healthy prepubertal boys. To study whether adrenal-derived steroids within the physiological range are associated with skeletal maturation, areal and volumetric bone mineral density (aBMD and vBMD) and bone geometry in healthy prepubertal and early pubertal boys. 98 healthy prepubertal and early pubertal boys (aged 6-14 y) were studied cross-sectionally. Androstenedione (A) and estrone (E1) were determined by liquid chromatography tandem mass spectrometry and DHEAS was determined by immunoassay. Whole body and lumbar spine aBMD and bone area were determined by dual-energy X-ray absorptiometry. Trabecular (distal site) and cortical (proximal site) vBMD and bone geometry were assessed at the non-dominant forearm and leg using peripheral QCT. Skeletal age was determined by X-ray of the left hand. Adrenal-derived steroids (DHEAS, A and E1) are positively associated with bone age in prepubertal and early pubertal children, independently of age. There are no associations between the adrenal-derived steroids and the studied parameters of bone size (lumbar spine and whole body bone area, trabecular or cortical area at the radius or tibia, periosteal circumference and cortical thickness at the radius or tibia) or BMD (aBMD or vBMD). In healthy prepubertal and early pubertal boys, serum adrenal-derived steroid levels, are associated with skeletal maturation, independently of age, but not with bone size or (v)BMD. Our data suggest that adrenal derived steroids are not implicated in the accretion of bone mass before puberty in boys. Copyright © 2014 Elsevier Inc. All rights reserved.

Pinpointing retrovirus entry sites in cells expressing alternatively spliced receptor isoforms by single virus imaging.

PubMed

Padilla-Parra, Sergi; Marin, Mariana; Kondo, Naoyuki; Melikyan, Gregory B

2014-06-16

The majority of viruses enter host cells via endocytosis. Current knowledge of viral entry pathways is largely based upon infectivity measurements following genetic and/or pharmacological interventions that disrupt vesicular trafficking and maturation. Imaging of single virus entry in living cells provides a powerful means to delineate viral trafficking pathways and entry sites under physiological conditions. Here, we visualized single avian retrovirus co-trafficking with markers for early (Rab5) and late (Rab7) endosomes, acidification of endosomal lumen and the resulting viral fusion measured by the viral content release into the cytoplasm. Virus-carrying vesicles either merged with the existing Rab5-positive early endosomes or slowly accumulated Rab5. The Rab5 recruitment to virus-carrying endosomes correlated with acidification of their lumen. Viral fusion occurred either in early (Rab5-positive) or intermediate (Rab5- and Rab7-positive) compartments. Interestingly, different isoforms of the cognate receptor directed virus entry from distinct endosomes. In cells expressing the transmembrane receptor, viruses preferentially entered and fused with slowly maturing early endosomes prior to accumulation of Rab7. By comparison, in cells expressing the GPI-anchored receptor, viruses entered both slowly and quickly maturing endosomes and fused with early (Rab5-positive) and intermediate (Rab5- and Rab7-positive) compartments. Since the rate of low pH-triggered fusion was independent of the receptor isoform, we concluded that the sites of virus entry are determined by the kinetic competition between endosome maturation and viral fusion. Our findings demonstrate the ability of this retrovirus to enter cells via alternative endocytic pathways and establish infection by releasing its content from distinct endosomal compartments.

ALL OUR SONS: THE DEVELOPMENTAL NEUROBIOLOGY AND NEUROENDOCRINOLOGY OF BOYS AT RISK.

PubMed

Schore, Allan N

2017-01-01

Why are boys at risk? To address this question, I use the perspective of regulation theory to offer a model of the deeper psychoneurobiological mechanisms that underlie the vulnerability of the developing male. The central thesis of this work dictates that significant gender differences are seen between male and female social and emotional functions in the earliest stages of development, and that these result from not only differences in sex hormones and social experiences but also in rates of male and female brain maturation, specifically in the early developing right brain. I present interdisciplinary research which indicates that the stress-regulating circuits of the male brain mature more slowly than those of the female in the prenatal, perinatal, and postnatal critical periods, and that this differential structural maturation is reflected in normal gender differences in right-brain attachment functions. Due to this maturational delay, developing males also are more vulnerable over a longer period of time to stressors in the social environment (attachment trauma) and toxins in the physical environment (endocrine disruptors) that negatively impact right-brain development. In terms of differences in gender-related psychopathology, I describe the early developmental neuroendocrinological and neurobiological mechanisms that are involved in the increased vulnerability of males to autism, early onset schizophrenia, attention deficit hyperactivity disorder, and conduct disorders as well as the epigenetic mechanisms that can account for the recent widespread increase of these disorders in U.S. culture. I also offer a clinical formulation of early assessments of boys at risk, discuss the impact of early childcare on male psychopathogenesis, and end with a neurobiological model of optimal adult male socioemotional functions. © 2017 Michigan Association for Infant Mental Health.

Evaluating the functional state of adult-born neurons in the adult dentate gyrus of the hippocampus: from birth to functional integration.

PubMed

Aguilar-Arredondo, Andrea; Arias, Clorinda; Zepeda, Angélica

2015-01-01

Hippocampal neurogenesis occurs in the adult brain in various species, including humans. A compelling question that arose when neurogenesis was accepted to occur in the adult dentate gyrus (DG) is whether new neurons become functionally relevant over time, which is key for interpreting their potential contributions to synaptic circuitry. The functional state of adult-born neurons has been evaluated using various methodological approaches, which have, in turn, yielded seemingly conflicting results regarding the timing of maturation and functional integration. Here, we review the contributions of different methodological approaches to addressing the maturation process of adult-born neurons and their functional state, discussing the contributions and limitations of each method. We aim to provide a framework for interpreting results based on the approaches currently used in neuroscience for evaluating functional integration. As shown by the experimental evidence, adult-born neurons are prone to respond from early stages, even when they are not yet fully integrated into circuits. The ongoing integration process for the newborn neurons is characterised by different features. However, they may contribute differently to the network depending on their maturation stage. When combined, the strategies used to date convey a comprehensive view of the functional development of newly born neurons while providing a framework for approaching the critical time at which new neurons become functionally integrated and influence brain function.

Toward Understanding How Early-Life Stress Reprograms Cognitive and Emotional Brain Networks.

PubMed

Chen, Yuncai; Baram, Tallie Z

2016-01-01

Vulnerability to emotional disorders including depression derives from interactions between genes and environment, especially during sensitive developmental periods. Adverse early-life experiences provoke the release and modify the expression of several stress mediators and neurotransmitters within specific brain regions. The interaction of these mediators with developing neurons and neuronal networks may lead to long-lasting structural and functional alterations associated with cognitive and emotional consequences. Although a vast body of work has linked quantitative and qualitative aspects of stress to adolescent and adult outcomes, a number of questions are unclear. What distinguishes 'normal' from pathologic or toxic stress? How are the effects of stress transformed into structural and functional changes in individual neurons and neuronal networks? Which ones are affected? We review these questions in the context of established and emerging studies. We introduce a novel concept regarding the origin of toxic early-life stress, stating that it may derive from specific patterns of environmental signals, especially those derived from the mother or caretaker. Fragmented and unpredictable patterns of maternal care behaviors induce a profound chronic stress. The aberrant patterns and rhythms of early-life sensory input might also directly and adversely influence the maturation of cognitive and emotional brain circuits, in analogy to visual and auditory brain systems. Thus, unpredictable, stress-provoking early-life experiences may influence adolescent cognitive and emotional outcomes by disrupting the maturation of the underlying brain networks. Comprehensive approaches and multiple levels of analysis are required to probe the protean consequences of early-life adversity on the developing brain. These involve integrated human and animal-model studies, and approaches ranging from in vivo imaging to novel neuroanatomical, molecular, epigenomic, and computational methodologies. Because early-life adversity is a powerful determinant of subsequent vulnerabilities to emotional and cognitive pathologies, understanding the underlying processes will have profound implications for the world's current and future children.

Late Maturation Steps Preceding Selective Nuclear Export and Egress of Progeny Parvovirus

PubMed Central

Wolfisberg, Raphael; Kempf, Christoph

2016-01-01

ABSTRACT Although the mechanism is not well understood, growing evidence indicates that the nonenveloped parvovirus minute virus of mice (MVM) may actively egress before passive release through cell lysis. We have dissected the late maturation steps of the intranuclear progeny with the aims of confirming the existence of active prelytic egress and identifying critical capsid rearrangements required to initiate the process. By performing anion-exchange chromatography (AEX), we separated intranuclear progeny particles by their net surface charges. Apart from empty capsids (EC), two distinct populations of full capsids (FC) arose in the nuclei of infected cells. The earliest population of FC to appear was infectious but, like EC, could not be actively exported from the nucleus. Further maturation of this early population, involving the phosphorylation of surface residues, gave rise to a second, late population with nuclear export potential. While capsid surface phosphorylation was strictly associated with nuclear export capacity, mutational analysis revealed that the phosphoserine-rich N terminus of VP2 (N-VP2) was dispensable, although it contributed to passive release. The reverse situation was observed for the incoming particles, which were dephosphorylated in the endosomes. Our results confirm the existence of active prelytic egress and reveal a late phosphorylation event occurring in the nucleus as a selective factor for initiating the process. IMPORTANCE In general, the process of egress of enveloped viruses is active and involves host cell membranes. However, the release of nonenveloped viruses seems to rely more on cell lysis. At least for some nonenveloped viruses, an active process before passive release by cell lysis has been reported, although the underlying mechanism remains poorly understood. By using the nonenveloped model parvovirus minute virus of mice, we could confirm the existence of an active process of nuclear export and further characterize the associated capsid maturation steps. Following DNA packaging in the nucleus, capsids required further modifications, involving the phosphorylation of surface residues, to acquire nuclear export potential. Inversely, those surface residues were dephosphorylated on entering capsids. These spatially controlled phosphorylation-dephosphorylation events concurred with the nuclear export-import potential required to complete the infectious cycle. PMID:27009963

Late Maturation Steps Preceding Selective Nuclear Export and Egress of Progeny Parvovirus.

PubMed

Wolfisberg, Raphael; Kempf, Christoph; Ros, Carlos

2016-06-01

Although the mechanism is not well understood, growing evidence indicates that the nonenveloped parvovirus minute virus of mice (MVM) may actively egress before passive release through cell lysis. We have dissected the late maturation steps of the intranuclear progeny with the aims of confirming the existence of active prelytic egress and identifying critical capsid rearrangements required to initiate the process. By performing anion-exchange chromatography (AEX), we separated intranuclear progeny particles by their net surface charges. Apart from empty capsids (EC), two distinct populations of full capsids (FC) arose in the nuclei of infected cells. The earliest population of FC to appear was infectious but, like EC, could not be actively exported from the nucleus. Further maturation of this early population, involving the phosphorylation of surface residues, gave rise to a second, late population with nuclear export potential. While capsid surface phosphorylation was strictly associated with nuclear export capacity, mutational analysis revealed that the phosphoserine-rich N terminus of VP2 (N-VP2) was dispensable, although it contributed to passive release. The reverse situation was observed for the incoming particles, which were dephosphorylated in the endosomes. Our results confirm the existence of active prelytic egress and reveal a late phosphorylation event occurring in the nucleus as a selective factor for initiating the process. In general, the process of egress of enveloped viruses is active and involves host cell membranes. However, the release of nonenveloped viruses seems to rely more on cell lysis. At least for some nonenveloped viruses, an active process before passive release by cell lysis has been reported, although the underlying mechanism remains poorly understood. By using the nonenveloped model parvovirus minute virus of mice, we could confirm the existence of an active process of nuclear export and further characterize the associated capsid maturation steps. Following DNA packaging in the nucleus, capsids required further modifications, involving the phosphorylation of surface residues, to acquire nuclear export potential. Inversely, those surface residues were dephosphorylated on entering capsids. These spatially controlled phosphorylation-dephosphorylation events concurred with the nuclear export-import potential required to complete the infectious cycle. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Spatiotemporal transcriptome provides insights into early fruit development of tomato (Solanum lycopersicum).

PubMed

Zhang, Shuaibin; Xu, Meng; Qiu, Zhengkun; Wang, Ketao; Du, Yongchen; Gu, Lianfeng; Cui, Xia

2016-03-18

Early fruit development is crucial for crop production in tomato. After fertilization, the ovary undergoes cell division and cell expansion before maturation. Although the roles of regulatory signals such as hormone and carbohydrate during early fruit development have been studied, the spatial distribution and the sequential initiation of these regulatory signals still need to be explored. Using the tomato cultivar 'Moneymaker', we analyzed the transcriptome of the ovule and the ovary wall/pericarp dissected from four different stages of the early developing fruits by stereoscope. These datasets give us the whole picture about the spatial and temporal signal distribution in early development of ovule and pericarp. Our results indicate that the hormone signal was initiated in both ovule and pericarp after fertilization. After that, different signals were activated in ovule and pericarp due to their distinct developmental processes. Our study provides spatiotemporal regulatory landscape of gene expression with sequential information which was not studied by previous work and further strengthens the comprehension of the regulatory and metabolic events controlling early fruit development.

Cortical Plasticity and Olfactory Function in Early Blindness

PubMed Central

Araneda, Rodrigo; Renier, Laurent A.; Rombaux, Philippe; Cuevas, Isabel; De Volder, Anne G.

2016-01-01

Over the last decade, functional brain imaging has provided insight to the maturation processes and has helped elucidate the pathophysiological mechanisms involved in brain plasticity in the absence of vision. In case of congenital blindness, drastic changes occur within the deafferented “visual” cortex that starts receiving and processing non visual inputs, including olfactory stimuli. This functional reorganization of the occipital cortex gives rise to compensatory perceptual and cognitive mechanisms that help blind persons achieve perceptual tasks, leading to superior olfactory abilities in these subjects. This view receives support from psychophysical testing, volumetric measurements and functional brain imaging studies in humans, which are presented here. PMID:27625596

Implementation of Maturity for Concrete Strength Measurement and Pay : Tech Summary

DOT National Transportation Integrated Search

2017-10-01

Using the maturity to determine concrete strength has been done for more than four decades. The concept was originally conceived in the late 1940s and early 1950s. More and more state and municipal DOTs are implementing its use every year, with some ...

Puberty and dispersal in a wild primate population

PubMed Central

Onyango, Patrick O.; Gesquiere, Laurence R.; Altmann, Jeanne; Alberts, Susan C.

2013-01-01

The onset of reproduction is preceded by a host of organismal adjustments and transformations, involving morphological, physiological, and behavioral changes. In highly social mammals, including humans and most nonhuman primates, the timing and nature of maturational processes is affected by the animal’s social milieu as well as its ecology. Here, we review a diverse set of findings on how maturation unfolds in wild baboons in the Amboseli basin of southern Kenya, and we place these findings in the context of other reports of maturational processes in primates and other mammals. First, we describe the series of events and processes that signal maturation in female and male baboons. Sex differences in age at both sexual maturity and first reproduction documented for this species are consistent with expectations of life history theory; males mature later than females and exhibit an adolescent growth spurt that is absent or minimal in females. Second, we summarize what we know about sources of variance in the timing of maturational processes including natal dispersal. In Amboseli, individuals in a food-enhanced group mature earlier than their wild-feeding counterparts, and offspring of high-ranking females mature earlier than offspring of low-ranking females. We also report on how genetic admixture, which occurs in Amboseli between two closely related baboon taxa, affects individual maturation schedules. PMID:23998668

Microarray and differential display identify genes involved in jasmonate-dependent anther development.

PubMed

Mandaokar, Ajin; Kumar, V Dinesh; Amway, Matt; Browse, John

2003-07-01

Jasmonate (JA) is a signaling compound essential for anther development and pollen fertility in Arabidopsis. Mutations that block the pathway of JA synthesis result into male sterility. To understand the processes of anther and pollen maturation, we used microarray and differential display approaches to compare gene expression pattern in anthers of wild-type Arabidopsis and the male-sterile mutant, opr3. Microarray experiment revealed 25 genes that were up-regulated more than 1.8-fold in wild-type anthers as compared to mutant anthers. Experiments based on differential display identified 13 additional genes up-regulated in wild-type anthers compared to opr3 for a total of 38 differentially expressed genes. Searches of the Arabidopsis and non-redundant databases disclosed known or likely functions for 28 of the 38 genes identified, while 10 genes encode proteins of unknown function. Northern blot analysis of eight representative clones as probes confirmed low expression in opr3 anthers compared with wild-type anthers. JA responsiveness of these same genes was also investigated by northern blot analysis of anther RNA isolated from wild-type and opr3 plants, In these experiments, four genes were induced in opr3 anthers within 0.5-1 h of JA treatment while the remaining genes were up-regulated only 1-8 h after JA application. None of these genes was induced by JA in anthers of the coil mutant that is deficient in JA responsiveness. The four early-induced genes in opr3 encode lipoxygenase, a putative bHLH transcription factor, epithiospecifier protein and an unknown protein. We propose that these and other early components may be involved in JA signaling and in the initiation of developmental processes. The four late genes encode an extensin-like protein, a peptide transporter and two unknown proteins, which may represent components required later in anther and pollen maturation. Transcript profiling has provided a successful approach to identify genes involved in anther and pollen maturation in Arabidopsis.

Defining the Application Readiness of Products when Developing Earth Observing Remote Sensing Data Products

NASA Astrophysics Data System (ADS)

Escobar, V. M.

2017-12-01

Satellite remote sensing technology has contributed to the transformation of multiple earth science domains, putting space observations at the forefront of innovation in Earth Science. With new satellite missions being launched every year, new types of Earth Science data are being incorporated into science models and decision-making systems in a broad array of organizations. These applications help hazard mitigation and decision-making in government, private, and civic institutions working to reduce its impact on human wellbeing. Policy guidance and knowledge of product maturity can influence mission design as well as development of product applications in user organizations. Ensuring that satellite missions serve both the scientific and user communities without becoming unfocused and overly expensive is a critical outcome from engagement of user communities. Tracking the applications and product maturity help improve the use of data. NASA's Applications Readiness Levels reduce cost and increase the confidence in applications. ARLs help identify areas where NASA products are most useful while allowing the user to leverage products in early development as well as those ready for operational uses. By considering the needs of the user community early on in the mission-design process, agencies can use ARLs to ensure that satellites meet the needs of multiple constituencies and the development of products are integrated into user organizations organically. ARLs and user integration provide a perspective on the maturity and readiness of a products ability to influence policy and decision-making. This paper describes the mission application development process at NASA and within the Earth Science Directorate. We present the successes and challenges faced by NASA data users and explain how ARLs helps link NASA science to the appropriate policies and decision frameworks. The methods presented here can be adapted to other programs and institutions seeking to rapidly move scientific research to applications that have societal impact.

Early Market TRL/MRL Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ronnebro, Ewa; Stetson, Ned

he focus of this report is TRL/MRL analysis of hydrogen storage; it documents the methodology and results of an effort to identify hydrogen storage technologies’ technical and manufacturing readiness for early market motive and non-motive applications and to provide a path forward toward commercialization. Motive applications include materials handling equipment (MHE) and ground support equipment (GSE), such as forklifts, tow tractors, and specialty vehicles such as golf carts, lawn mowers and wheel chairs. Non-motive applications are portable, stationary or auxiliary power units (APUs) and include portable laptops, backup power, remote sensor power, and auxiliary power for recreational vehicles, hotels, hospitals,more » etc. Hydrogen storage technologies assessed include metal hydrides, chemical hydrides, sorbents, gaseous storage, and liquid storage. The assessments are based on a combination of Technology Readiness Level (TRL) and Manufacturing Readiness Level (MRL) designations that enable evaluation of hydrogen storage technologies at varying levels of development. The manufacturing status could be established from eight risk elements: Technical Maturity, Design, Materials, Cost & Funding, Process Capability, Personnel, Facilities and Manufacturing Planning. This approach provides a logical methodology and roadmap to enable the identification of hydrogen storage technologies, their advantages/disadvantages, gaps and R&D needs on an unbiased and transparent scale that is easily communicated to interagency partners. This technology readiness assessment (TRA) report documents the process used to conduct the TRA/MRA (technology and manufacturing readiness assessment), reports the TRL and MRL for each assessed technology and provides recommendations based on the findings. To investigate the state of the art and needs to mature the technologies, PNNL prepared a questionnaire to assign TRL and MRL for each hydrogen storage technology. The questionnaire was sent to identified hydrogen storage technology developers and manufacturers who were asked to perform a self-assessment. We included both domestic and international organizations including U.S. national laboratories, U.S. companies, European companies and Japanese companies. PNNL collected the data and performed an analysis to deduce the level of maturity and to provide program recommendations.« less

Development of somatosensory-evoked potentials in foetal sheep: effects of betamethasone.

PubMed

Anegroaie, P; Frasch, M G; Rupprecht, S; Antonow-Schlorke, I; Müller, T; Schubert, H; Witte, O W; Schwab, M

2017-05-01

Antenatal glucocorticoids are used to accelerate foetal lung maturation in babies threatened with premature labour. We examined the influence of glucocorticoids on functional and structural maturation of the central somatosensory pathway in foetal sheep. Somatosensory-evoked potentials (SEP) reflect processing of somatosensory stimuli. SEP latencies are determined by afferent stimuli transmission while SEP amplitudes reveal cerebral processing. After chronic instrumentation of foetal sheep, mothers received saline (n = 9) or three courses of betamethasone (human equivalent dose of 2 × 110 μg kg -1 betamethasone i.m. 24 h apart, n = 12) at 0.7, 0.75 and 0.8 of gestational age. Trigeminal SEP were evoked prior to, 4 and 24 h after each injection and at 0.8 of gestational age before brains were histologically processed. Somatosensory-evoked potentials were already detectable at 0.7 of gestation age. The early and late responses N20 and N200 were the only reproducible peaks over the entire study period. With advancing gestational age, SEP latencies decreased but amplitudes remained unchanged. Acutely, betamethasone did not affect SEP latencies and amplitudes 4 and 24 h following administration. Chronically, betamethasone delayed developmental decrease in the N200 but not N20 latency by 2 weeks without affecting amplitudes. In parallel, betamethasone decreased subcortical white matter myelination but did not affect network formation and synaptic density in the somatosensory cortex. Somatosensory stimuli are already processed by the foetal cerebral cortex at the beginning of the third trimester. Subsequent developmental decrease in SEP latencies suggests ongoing maturation of afferent sensory transmission. Antenatal glucocorticoids affect structural and functional development of the somatosensory system with specific effects at subcortical level. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Early Cannabis Use, Polygenic Risk Score for Schizophrenia and Brain Maturation in Adolescence.

PubMed

French, Leon; Gray, Courtney; Leonard, Gabriel; Perron, Michel; Pike, G Bruce; Richer, Louis; Séguin, Jean R; Veillette, Suzanne; Evans, C John; Artiges, Eric; Banaschewski, Tobias; Bokde, Arun W L; Bromberg, Uli; Bruehl, Ruediger; Buchel, Christian; Cattrell, Anna; Conrod, Patricia J; Flor, Herta; Frouin, Vincent; Gallinat, Jurgen; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Lemaitre, Herve; Martinot, Jean-Luc; Nees, Frauke; Orfanos, Dimitri Papadopoulos; Pangelinan, Melissa Marie; Poustka, Luise; Rietschel, Marcella; Smolka, Michael N; Walter, Henrik; Whelan, Robert; Timpson, Nic J; Schumann, Gunter; Smith, George Davey; Pausova, Zdenka; Paus, Tomáš

2015-10-01

Cannabis use during adolescence is known to increase the risk for schizophrenia in men. Sex differences in the dynamics of brain maturation during adolescence may be of particular importance with regard to vulnerability of the male brain to cannabis exposure. To evaluate whether the association between cannabis use and cortical maturation in adolescents is moderated by a polygenic risk score for schizophrenia. Observation of 3 population-based samples included initial analysis in 1024 adolescents of both sexes from the Canadian Saguenay Youth Study (SYS) and follow-up in 426 adolescents of both sexes from the IMAGEN Study from 8 European cities and 504 male youth from the Avon Longitudinal Study of Parents and Children (ALSPAC) based in England. A total of 1577 participants (aged 12-21 years; 899 [57.0%] male) had (1) information about cannabis use; (2) imaging studies of the brain; and (3) a polygenic risk score for schizophrenia across 108 genetic loci identified by the Psychiatric Genomics Consortium. Data analysis was performed from March 1 through December 31, 2014. Cortical thickness derived from T1-weighted magnetic resonance images. Linear regression tests were used to assess the relationships between cannabis use, cortical thickness, and risk score. Across the 3 samples of 1574 participants, a negative association was observed between cannabis use in early adolescence and cortical thickness in male participants with a high polygenic risk score. This observation was not the case for low-risk male participants or for the low- or high-risk female participants. Thus, in SYS male participants, cannabis use interacted with risk score vis-à-vis cortical thickness (P = .009); higher scores were associated with lower thickness only in males who used cannabis. Similarly, in the IMAGEN male participants, cannabis use interacted with increased risk score vis-à-vis a change in decreasing cortical thickness from 14.5 to 18.5 years of age (t137 = -2.36; P = .02). Finally, in the ALSPAC high-risk group of male participants, those who used cannabis most frequently (≥61 occasions) had lower cortical thickness than those who never used cannabis (difference in cortical thickness, 0.07 [95% CI, 0.01-0.12]; P = .02) and those with light use (<5 occasions) (difference in cortical thickness, 0.11 [95% CI, 0.03-0.18]; P = .004). Cannabis use in early adolescence moderates the association between the genetic risk for schizophrenia and cortical maturation among male individuals. This finding implicates processes underlying cortical maturation in mediating the link between cannabis use and liability to schizophrenia.

Epigenetic and gene expression changes in the adolescent brain: What have we learned from animal models?

PubMed

Mychasiuk, Richelle; Metz, Gerlinde A S

2016-11-01

Adolescence is defined as the gradual period of transition between childhood and adulthood that is characterized by significant brain maturation, growth spurts, sexual maturation, and heightened social interaction. Although originally believed to be a uniquely human aspect of development, rodent and non-human primates demonstrate maturational patterns that distinctly support an adolescent stage. As epigenetic processes are essential for development and differentiation, but also transpire in mature cells in response to environmental influences, they are an important aspect of adolescent brain maturation. The purpose of this review article was to examine epigenetic programming in animal models of brain maturation during adolescence. The discussion focuses on animal models to examine three main concepts; epigenetic processes involved in normal adolescent brain maturation, the influence of fetal programming on adolescent brain development and the epigenome, and finally, postnatal experiences such as exercise and drugs that modify epigenetic processes important for adolescent brain maturation. This corollary emphasizes the utility of animal models to further our understanding of complex processes such as epigenetic regulation and brain development. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reproductive strategy, sexual development and attraction to facial characteristics

PubMed Central

Cornwell, R. Elisabeth; Law Smith, Miriam J; Boothroyd, Lynda G; Moore, Fhionna R; Davis, Hasker P; Stirrat, Michael; Tiddeman, Bernard; Perrett, David I

2006-01-01

Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate sexual maturation and reproduction. Early age of menarche is associated with absence of younger siblings, absence of a father figure during early life and increased weight. Father absence during early life is also associated with early marriage, pregnancy and divorce. Choice of partner characteristics is critical to successful implementation of sexual strategies. It has been suggested that sexually dimorphic traits (including those evident in the face) signal high-quality immune function and reproductive status. Masculinity in males has also been associated with low investment in mate and offspring. Thus, women's reproductive strategy should be matched to the probability of male investment, hence to male masculinity. Our review leads us to predict associations between the rate of sexual maturation and adult preferences for facial characteristics (enhanced sexual dimorphism and attractiveness). We find for men, engaging in sex at an early age is related to an increased preference for feminized female faces. Similarly, for women, the earlier the age of first sex the greater the preference for masculinity in opposite-sex faces. When we controlled sexual dimorphism in male faces, the speed of sexual development in women was not associated with differences in preference for male facial attractiveness. These developmental influences on partner choice were not mediated by self-rated attractiveness or parental relationships. We conclude that individuals assort in preferences based on the rapidity of their sexual development. Fast developing individuals prefer opposite-sex partners with an increased level of sexually dimorphic facial characteristics. PMID:17118929

Reproductive strategy, sexual development and attraction to facial characteristics.

PubMed

Cornwell, R Elisabeth; Law Smith, Miriam J; Boothroyd, Lynda G; Moore, Fhionna R; Davis, Hasker P; Stirrat, Michael; Tiddeman, Bernard; Perrett, David I

2006-12-29

Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate sexual maturation and reproduction. Early age of menarche is associated with absence of younger siblings, absence of a father figure during early life and increased weight. Father absence during early life is also associated with early marriage, pregnancy and divorce. Choice of partner characteristics is critical to successful implementation of sexual strategies. It has been suggested that sexually dimorphic traits (including those evident in the face) signal high-quality immune function and reproductive status. Masculinity in males has also been associated with low investment in mate and offspring. Thus, women's reproductive strategy should be matched to the probability of male investment, hence to male masculinity. Our review leads us to predict associations between the rate of sexual maturation and adult preferences for facial characteristics (enhanced sexual dimorphism and attractiveness). We find for men, engaging in sex at an early age is related to an increased preference for feminized female faces. Similarly, for women, the earlier the age of first sex the greater the preference for masculinity in opposite-sex faces. When we controlled sexual dimorphism in male faces, the speed of sexual development in women was not associated with differences in preference for male facial attractiveness. These developmental influences on partner choice were not mediated by self-rated attractiveness or parental relationships. We conclude that individuals assort in preferences based on the rapidity of their sexual development. Fast developing individuals prefer opposite-sex partners with an increased level of sexually dimorphic facial characteristics.

The discovery and early understanding of leukemia.

PubMed

Kampen, Kim R

2012-01-01

The early history of leukemia reaches back 200 years. In 1811, Peter Cullen defined a case of splenitis acutus with unexplainable milky blood. Alfred Velpeau defined the leukemia associated symptoms, and observed pus in the blood vessels (1825). Alfred Donné detected a maturation arrest of the white blood cells (1844). John Bennett named the disease leucocythemia, based on the microscopic accumulation of purulent leucocytes (1845). That same year, Rudolf Virchow defined a reversed white and red blood cell balance. He introduced the disease as leukämie in 1847. Henry Fuller performed the first microscopic diagnose of a leukemic patient during life (1846). This gradual process brought us towards our current understanding of this complex disease. Copyright © 2011 Elsevier Ltd. All rights reserved.

'NuMex Las Cruces' Cayenne pepper

USDA-ARS?s Scientific Manuscript database

‘NuMex Las Cruces’ is a high-yielding, high-heat, cayenne pepper with a maturity similar to that of ‘Large Red Thick’, an early maturing cayenne cultivar. In addition, it possesses resistance to curly top virus, having resistance to at least three Curtovirus species: Beet curly top virus (BCTV; for...

Converging on a core cognitive deficit: the impact of various neurodevelopmental insults on cognitive control

PubMed Central

O'Reilly, Kally C.; Kao, Hsin-Yi; Lee, Heekyung; Fenton, André A.

2014-01-01

Despite substantial effort and immense need, the treatment options for major neuropsychiatric illnesses like schizophrenia are limited and largely ineffective at improving the most debilitating cognitive symptoms that are central to mental illness. These symptoms include cognitive control deficits, the inability to selectively use information that is currently relevant and ignore what is currently irrelevant. Contemporary attempts to accelerate progress are in part founded on an effort to reconceptualize neuropsychiatric illness as a disorder of neural development. This neuro-developmental framework emphasizes abnormal neural circuits on the one hand, and on the other, it suggests there are therapeutic opportunities to exploit the developmental processes of excitatory neuron pruning, inhibitory neuron proliferation, elaboration of myelination, and other circuit refinements that extend through adolescence and into early adulthood. We have crafted a preclinical research program aimed at cognition failures that may be relevant to mental illness. By working with a variety of neurodevelopmental rodent models, we strive to identify a common pathophysiology that underlies cognitive control failure as well as a common strategy for improving cognition in the face of neural circuit abnormalities. Here we review our work to characterize cognitive control deficits in rats with a neonatal ventral hippocampus lesion and rats that were exposed to Methylazoxymethanol acetate (MAM) in utero. We review our findings as they pertain to early developmental processes, including neurogenesis, as well as the power of cognitive experience to refine neural circuit function within the mature and maturing brain's cognitive circuitry. PMID:24966811

Profiling of differentially expressed genes critical to storage root development in hydroponically and in-vitro grown sweetpotato for space farming

NASA Astrophysics Data System (ADS)

Egnin, M.; Gao, H.; He, G.; Woullard, F.; Mortley, D.; Scoffield, J.; Bey, B.; Quain, M.; Prakash, C. S.; Bonsi, C.

Environment is known to have significant effects on the nutrient content and quality of crop plants especially through its impact on the temporal and spatial expression of genes Little is known about the molecular changes and harvest index in plants in response to microgravity Sweetpotato underline Ipomoea underline batatas L Lam is one of the most important root crops and an excellent NASA crop for space farming to provide essential nutrients to sustain human life on long-term space missions The initiation and development of storage root formation is one of the most critical processes determining yield of sweetpotato The molecular mechanism of storage root initiation and development in sweetpotato is poorly understood To this end knowledge of gravity perception the genetic and molecular nature of the induction process of storage root will tremendously help improve on sweetpotato harvest index for space farming cDNA-AFLP techniques were employed to investigate temporal and spatial expressions to gain molecular insights and identify transcripts differentially expressed during early stages of sweetpotato storage root development Two hydroponically grown cultivars using Nutrient Film Technology NFT and microstorage roots were evaluated TU-82-155 an early maturing 90 DAP with orange flesh and tinge red skin and PI318846-3 a late maturing 135 DAP with white flesh and off-yellow skin were compared for differential genes expression during storage root development at 14 21 28 35 and 45 DAP Total RNA was isolated from

Changes in polyphenolics during maturation of Java plum (Syzygium cumini Lam.).

PubMed

Lestario, Lydia Ninan; Howard, Luke R; Brownmiller, Cindi; Stebbins, Nathan B; Liyanage, Rohana; Lay, Jackson O

2017-10-01

Java plum (Syzygium cumini Lam.) is a rich source of polyphenolics with many purported health benefits, but the effect of maturation on polyphenolic content is unknown. Freeze-dried samples of Java plum from seven different maturity stages were analyzed for anthocyanin, flavonol, flavanonol and hydrolysable tannin composition by HPLC. Anthocyanins were first detected at the green-pink stage of maturity and increased throughout maturation with the largest increase occurring from the dark purple to black stages of maturation. Levels of gallotannins, ellagitannins, flavonols, gallic acid and ellagic acid were highest at early stages of maturation and decreased as the fruit ripened. For production of antioxidant-rich nutraceutical ingredients, fruit should be harvested immature to obtain extracts rich in hydrolysable tannins and flavonols. The exceptional anthocyanin content of black fruit may prove useful as a source of a natural colorant. Copyright © 2017 Elsevier Ltd. All rights reserved.

Regulatory Peptides in Plants.

PubMed

Vanyushin, B F; Ashapkin, V V; Aleksandrushkina, N I

2017-02-01

Many different peptides regulating cell differentiation, growth, and development are found in plants. Peptides participate in regulation of plant ontogenesis starting from pollination, pollen tube growth, and the very early stages of embryogenesis, including formation of embryo and endosperm. They direct differentiation of meristematic stem cells, formation of tissues and individual organs, take part in regulation of aging, fruit maturation, and abscission of plant parts associated with apoptosis. Biological activity of peptides is observed at very low concentrations, and it has mainly signal nature and hormonal character. "Mature" peptides appear mainly due to processing of protein precursors with (or without) additional enzymatic modifications. Plant peptides differ in origin, structure, and functional properties. Their specific action is due to binding with respective receptors and interactions with various proteins and other factors. Peptides can also regulate physiological functions by direct peptide-protein interactions. Peptide action is coordinated with the action of known phytohormones (auxins, cytokinins, and others); thus, peptides control phytohormonal signal pathways.

Serial profiles of electrostatic potential in five New Mexico thunderstorms

NASA Astrophysics Data System (ADS)

Stolzenburg, Maribeth; Marshall, Thomas C.

2008-07-01

Profiles of electric potential (V) integrated from balloon-borne electric field (E) measurements are used to investigate the electrical evolution of thunderstorms over the mountains in central New Mexico. With sequential soundings through multiple storms, the time skew associated with obtaining V from a noninstantaneous sounding is also studied. The data show that a basic V profile, with a maximum above a minimum, forms in the early stage of the storm and is maintained throughout its mature stage. Series of soundings from individual storms show only a gradual evolution in the V profile from the early through the mature stage, as the extrema descend in altitude and become shallower and vertically closer together. More evolution occurs in the late stage, when the shape of the V profile reverses to have a minimum above a maximum. The 17 V(z) profiles from the mature stage of five different storms are also very similar in overall shape, suggesting that the basic shape is not significantly affected by differences in lightning flash rate among these storms. The findings indicate that the potential profile during a typical sounding in the mature stage is relatively stable, and the overall shape of the mature stage V profile does not change markedly on the time scale of a particular balloon sounding (10-30 min) through New Mexico mountain storms. Thus time-skew problems in the V profiles are minor during a storm's mature stage.

Early musical training is linked to gray matter structure in the ventral premotor cortex and auditory-motor rhythm synchronization performance.

PubMed

Bailey, Jennifer Anne; Zatorre, Robert J; Penhune, Virginia B

2014-04-01

Evidence in animals and humans indicates that there are sensitive periods during development, times when experience or stimulation has a greater influence on behavior and brain structure. Sensitive periods are the result of an interaction between maturational processes and experience-dependent plasticity mechanisms. Previous work from our laboratory has shown that adult musicians who begin training before the age of 7 show enhancements in behavior and white matter structure compared with those who begin later. Plastic changes in white matter and gray matter are hypothesized to co-occur; therefore, the current study investigated possible differences in gray matter structure between early-trained (ET; <7) and late-trained (LT; >7) musicians, matched for years of experience. Gray matter structure was assessed using voxel-wise analysis techniques (optimized voxel-based morphometry, traditional voxel-based morphometry, and deformation-based morphometry) and surface-based measures (cortical thickness, surface area and mean curvature). Deformation-based morphometry analyses identified group differences between ET and LT musicians in right ventral premotor cortex (vPMC), which correlated with performance on an auditory motor synchronization task and with age of onset of musical training. In addition, cortical surface area in vPMC was greater for ET musicians. These results are consistent with evidence that premotor cortex shows greatest maturational change between the ages of 6-9 years and that this region is important for integrating auditory and motor information. We propose that the auditory and motor interactions required by musical practice drive plasticity in vPMC and that this plasticity is greatest when maturation is near its peak.

Immunoglobulin D (IgD)-deficient mice reveal an auxiliary receptor function for IgD in antigen-mediated recruitment of B cells

PubMed Central

1993-01-01

To assess the role of immunoglobulin D (IgD) in vivo we generated IgD- deficient mice by gene targeting and studied B cell development and function in the absence of IgD expression. In the mutant animals, conventional and CD5-positive (B1) B cells are present in normal numbers, and the expression of the surface markers CD22 and CD23 in the compartment of conventional B cells indicates acquisition of a mature phenotype. As in wild-type animals, most of the peripheral B cells are resting cells. The IgD-deficient mice respond well to T cell- independent and -dependent antigens. However, in heterozygous mutant animals, B cells expressing the wild type IgH locus are overrepresented in the peripheral B cell pool, and T cell-dependent IgG1 responses are further dominated by B cells expressing the wild-type allele. Similarly, in homozygous mutant (IgD-deficient) animals, affinity maturation is delayed in the early primary response compared to control animals, although the mutants are capable of generating high affinity B cell memory. Thus, rather than being involved in major regulatory processes as had been suggested, IgD seems to function as an antigen receptor optimized for efficient recruitment of B cells into antigen- driven responses. The IgD-mediated acceleration of affinity maturation in the early phase of the T cell-dependent primary response may confer to the animal a critical advantage in the defense against pathogens. PMID:8418208

Technique for obtaining highly enriched, quiescent immature Langerhans cells suitable for ex vivo assays.

PubMed

Tchou, Isabelle; Sabido, Odile; Lambert, Claude; Misery, Laurent; Garraud, Olivier; Genin, Christian

2003-03-03

Epidermis and surface epithelium-dendritic cells comprise of immature cells termed Langerhans cells (LCs), which express characteristically the Birbeck granules, along with surface markers such as CD1a. These cells can capture a pathogen and then migrate and differentiate to a more mature stage. During this maturation process, dentritic cells express surface markers differentially. In physio-pathological models of infection where LCs are involved, it is critically important to ensure that the LCs tested in vitro are still immature and are not artefactually matured-dentritic cells. For experimental purposes, LCs were isolated from skin epidermis obtained from patients undergoing plastic surgery. This work thus aimed at collecting fresh LCs ex vivo and at testing the cells for phenotypic and functional characteristics of the immature stage. After mechanic disruption of the epidermis and proceeding for single cell suspension obtaining, two methods for purification were tested in parallel: (a) a positive immuno-magnetic separation by anti-CD1a-coated beads and (b) a purely mechanic purification system based on a three-step Ficoll floatation process. Both systems were equally efficient in terms of purification and yield. By using flow cytometry phenotyping, we have demonstrated that the use of magnetic beads led to some degree of maturation of CD1a(+) LCs, contrary to the repeated Ficoll floatation. This work calls attention for the use of certain monoclonal antibodies such as anti-CD1a to purify immature dendritic cells as they pre-activate these cells. Pre-activation would render a number of assays on the early events of LC physiology invalid, contrary to the purification of fresh skin epidermis LCs by means of a repeated Ficoll floatation.

Perinatal stress and early life programming of lung structure and function

PubMed Central

Wright, Rosalind J.

2010-01-01

Exposure to environmental toxins during critical periods of prenatal and/or postnatal development may alter the normal course of lung morphogenesis and maturation, potentially resulting in changes that affect both structure and function of the respiratory system. Moreover, these early effects may persist into adult life magnifying the potential public health impact. Aberrant or excessive pro-inflammatory immune responses, occurring both locally and systemically, that result in inflammatory damage to the airway are a central determinant of lung structure-function changes throughout life. Disruption of neuroendocrine function in early development, specifically the hypothalamic-pituitary-adrenal (HPA) axis, may alter functional status of the immune system. Autonomic nervous system (ANS) function (sympathovagal imbalance) is another integral component of airway function and immunity in childhood. This overview discusses the evidence linking psychological factors to alterations in these interrelated physiological processes that may, in turn, influence childhood lung function and identifies gaps in our understanding. PMID:20080145

Late maturation of visual spatial integration in humans

PubMed Central

Kovács, Ilona; Kozma, Petra; Fehér, Ákos; Benedek, György

1999-01-01

Visual development is thought to be completed at an early age. We suggest that the maturation of the visual brain is not homogeneous: functions with greater need for early availability, such as visuomotor control, mature earlier, and the development of other visual functions may extend well into childhood. We found significant improvement in children between 5 and 14 years in visual spatial integration by using a contour-detection task. The data show that long-range spatial interactions—subserving the integration of orientational information across the visual field—span a shorter spatial range in children than in adults. Performance in the task improves in a cue-specific manner with practice, which indicates the participation of fairly low-level perceptual mechanisms. We interpret our findings in terms of a protracted development of ventral visual-stream function in humans. PMID:10518600

In vitro protease cleavage and computer simulations reveal the HIV-1 capsid maturation pathway

NASA Astrophysics Data System (ADS)

Ning, Jiying; Erdemci-Tandogan, Gonca; Yufenyuy, Ernest L.; Wagner, Jef; Himes, Benjamin A.; Zhao, Gongpu; Aiken, Christopher; Zandi, Roya; Zhang, Peijun

2016-12-01

HIV-1 virions assemble as immature particles containing Gag polyproteins that are processed by the viral protease into individual components, resulting in the formation of mature infectious particles. There are two competing models for the process of forming the mature HIV-1 core: the disassembly and de novo reassembly model and the non-diffusional displacive model. To study the maturation pathway, we simulate HIV-1 maturation in vitro by digesting immature particles and assembled virus-like particles with recombinant HIV-1 protease and monitor the process with biochemical assays and cryoEM structural analysis in parallel. Processing of Gag in vitro is accurate and efficient and results in both soluble capsid protein and conical or tubular capsid assemblies, seemingly converted from immature Gag particles. Computer simulations further reveal probable assembly pathways of HIV-1 capsid formation. Combining the experimental data and computer simulations, our results suggest a sequential combination of both displacive and disassembly/reassembly processes for HIV-1 maturation.

E-learning process maturity level: a conceptual framework

NASA Astrophysics Data System (ADS)

Rahmah, A.; Santoso, H. B.; Hasibuan, Z. A.

2018-03-01

ICT advancement is a sure thing with the impact influencing many domains, including learning in both formal and informal situations. It leads to a new mindset that we should not only utilize the given ICT to support the learning process, but also improve it gradually involving a lot of factors. These phenomenon is called e-learning process evolution. Accordingly, this study attempts to explore maturity level concept to provide the improvement direction gradually and progression monitoring for the individual e-learning process. Extensive literature review, observation, and forming constructs are conducted to develop a conceptual framework for e-learning process maturity level. The conceptual framework consists of learner, e-learning process, continuous improvement, evolution of e-learning process, technology, and learning objectives. Whilst, evolution of e-learning process depicted as current versus expected conditions of e-learning process maturity level. The study concludes that from the e-learning process maturity level conceptual framework, it may guide the evolution roadmap for e-learning process, accelerate the evolution, and decrease the negative impact of ICT. The conceptual framework will be verified and tested in the future study.

Adolescent exposure to THC in female rats disrupts developmental changes in the prefrontal cortex.

PubMed

Rubino, Tiziana; Prini, Pamela; Piscitelli, Fabiana; Zamberletti, Erica; Trusel, Massimo; Melis, Miriam; Sagheddu, Claudia; Ligresti, Alessia; Tonini, Raffaella; Di Marzo, Vincenzo; Parolaro, Daniela

2015-01-01

Current concepts suggest that exposure to THC during adolescence may act as a risk factor for the development of psychiatric disorders later in life. However, the molecular underpinnings of this vulnerability are still poorly understood. To analyze this, we investigated whether and how THC exposure in female rats interferes with different maturational events occurring in the prefrontal cortex during adolescence through biochemical, pharmacological and electrophysiological means. We found that the endocannabinoid system undergoes maturational processes during adolescence and that THC exposure disrupts them, leading to impairment of both endocannabinoid signaling and endocannabinoid-mediated LTD in the adult prefrontal cortex. THC also altered the maturational fluctuations of NMDA subunits, leading to larger amounts of gluN2B at adulthood. Adult animals exposed to THC during adolescence also showed increased AMPA gluA1 with no changes in gluA2 subunits. Finally, adolescent THC exposure altered cognition at adulthood. All these effects seem to be triggered by the disruption of the physiological role played by the endocannabinoid system during adolescence. Indeed, blockade of CB1 receptors from early to late adolescence seems to prevent the occurrence of pruning at glutamatergic synapses. These results suggest that vulnerability of adolescent female rats to long-lasting THC adverse effects might partly reside in disruption of the pivotal role played by the endocannabinoid system in the prefrontal cortex maturation. Copyright © 2014 Elsevier Inc. All rights reserved.

Bottlenecks in bog pine multiplication by somatic embryogenesis and their visualization with the environmental scanning electron microscope.

PubMed

Vlašínová, Helena; Neděla, Vilem; Đorđević, Biljana; Havel, Ladislav

2017-07-01

Somatic embryogenesis (SE) is an important biotechnological technique used for the propagation of many pine species in vitro. However, in bog pine, one of the most endangered tree species in the Czech Republic, limitations were observed, which negatively influenced the development and further germination of somatic embryos. Although initiation frequency was very low-0.95 %, all obtained cell lines were subjected to maturation. The best responding cell line (BC1) was used and subjected to six different variants of the maturation media. The media on which the highest number of early-precotyledonary/cotyledonary somatic embryos was formed was supplemented with 121 μM abscisic acid (ABA) and with 6 % maltose. In the end of maturation experiments, different abnormalities in formation of somatic embryos were observed. For visualization and identification of abnormalities in meristem development during proliferation and maturation processes, the environmental scanning electron microscope was used. In comparison to the classical light microscope, the non-commercial environmental scanning electron microscope AQUASEM II has been found as a very useful tool for the quick recognition of apical meristem disruption and abnormal development. To our knowledge, this is the first report discussing somatic embryogenesis in bog pine. Based on this observation, the cultivation procedure could be enhanced and the method for SE of bog pine optimized.

Gross Motor Development, Movement Abnormalities, and Early Identification of Autism

PubMed Central

Young, Gregory S.; Goldring, Stacy; Greiss-Hess, Laura; Herrera, Adriana M.; Steele, Joel; Macari, Suzanne; Hepburn, Susan; Rogers, Sally J.

2015-01-01

Gross motor development (supine, prone, rolling, sitting, crawling, walking) and movement abnormalities were examined in the home videos of infants later diagnosed with autism (regression and no regression subgroups), developmental delays (DD), or typical development. Group differences in maturity were found for walking, prone, and supine, with the DD and Autism-No Regression groups both showing later developing motor maturity than typical children. The only statistically significant differences in movement abnormalities were in the DD group; the two autism groups did not differ from the typical group in rates of movement abnormalities or lack of protective responses. These findings do not replicate previous investigations suggesting that early motor abnormalities seen on home video can assist in early identification of autism. PMID:17805956

Executive Functioning, Cortisol Reactivity, and Symptoms of Psychopathology in Girls with Premature Adrenarche

PubMed Central

Sontag-Padilla, Lisa M.; Dorn, Lorah D.; Tissot, Abbigail; Susman, Elizabeth J.; Beers, Sue R.; Rose, Susan R.

2012-01-01

The study examined the interaction between early maturational timing [as measured by premature adrenarche (PA)] and executive functioning and cortisol reactivity on symptoms of psychopathology. The study included 76 girls aged 6 through 8 years (mean = 7.50; SD = .85) with PA (n = 40) and on-time adrenarche (n = 36). Girls completed a battery of psychological and neuropsychological tests and blood sampling for cortisol. Parents completed the Child Behavior Checklist. Results demonstrated that girls with PA with lower levels of executive functioning had higher externalizing and anxious symptoms compared to other girls. Additionally, girls with PA who demonstrated increases in serum cortisol had higher externalizing symptoms than those with stable patterns. Finally, girls with PA who demonstrated decreases in cortisol reported higher depressive symptoms. Findings from this study provide important information concerning the impact of cognitive functioning and stress reactivity on adjustment to early maturation in girls with PA. Results of this research may inform screening and intervention efforts for girls who may be at greatest risk for emotional and behavioral problems as a result of early maturation. PMID:22293005

PSD-95 is post-transcriptionally repressed during early neural development by PTBP1 and PTBP2.

PubMed

Zheng, Sika; Gray, Erin E; Chawla, Geetanjali; Porse, Bo Torben; O'Dell, Thomas J; Black, Douglas L

2012-01-15

Postsynaptic density protein 95 (PSD-95) is essential for synaptic maturation and plasticity. Although its synaptic regulation has been widely studied, the control of PSD-95 cellular expression is not understood. We found that Psd-95 was controlled post-transcriptionally during neural development. Psd-95 was transcribed early in mouse embryonic brain, but most of its product transcripts were degraded. The polypyrimidine tract binding proteins PTBP1 and PTBP2 repressed Psd-95 (also known as Dlg4) exon 18 splicing, leading to premature translation termination and nonsense-mediated mRNA decay. The loss of first PTBP1 and then of PTBP2 during embryonic development allowed splicing of exon 18 and expression of PSD-95 late in neuronal maturation. Re-expression of PTBP1 or PTBP2 in differentiated neurons inhibited PSD-95 expression and impaired the development of glutamatergic synapses. Thus, expression of PSD-95 during early neural development is controlled at the RNA level by two PTB proteins whose sequential downregulation is necessary for synapse maturation.

The capsid-spacer peptide 1 Gag processing intermediate is a dominant-negative inhibitor of HIV-1 maturation.

PubMed

Checkley, Mary Ann; Luttge, Benjamin G; Soheilian, Ferri; Nagashima, Kunio; Freed, Eric O

2010-04-25

The human immunodeficiency virus type 1 (HIV-1) maturation inhibitor bevirimat disrupts virus replication by inhibiting the cleavage of the capsid-spacer peptide 1 (CA-SP1) Gag processing intermediate to mature CA. The observation that bevirimat delays but does not completely block CA-SP1 processing suggests that the presence of uncleaved CA-SP1 may disrupt the maturation process in trans. In this study, we validate this hypothesis by using a genetic approach to demonstrate that a non-cleavable CA-SP1 mutant exerts a dominant-negative effect on maturation of wild-type HIV-1. In contrast, a mutant in which cleavage can occur internally within SP1 is significantly less potent as a dominant-negative inhibitor. We also show that bevirimat blocks processing at both the major CA-SP1 cleavage site and the internal site. These data underscore the importance of full CA-SP1 processing for HIV-1 maturation and highlight the therapeutic potential of inhibitors that target this Gag cleavage event. Published by Elsevier Inc.

Maturation of the human fetal startle response: evidence for sex-specific maturation of the human fetus.

PubMed

Buss, Claudia; Davis, Elysia Poggi; Class, Quetzal A; Gierczak, Matt; Pattillo, Carol; Glynn, Laura M; Sandman, Curt A

2009-10-01

Despite the evidence for early fetal experience exerting programming influences on later neurological development and health risk, very few prospective studies of human fetal behavior have been reported. In a prospective longitudinal study, fetal nervous system maturation was serially assessed by monitoring fetal heart rate (FHR) responses to vibroacoustic stimulation (VAS) in 191 maternal/fetal dyads. Responses were not detected at 26 weeks gestational age (GA). Sex-specific, age-characteristic changes in the FHR response to VAS were observed by 31 weeks' GA. Males showed larger responses and continued to exhibit maturational changes until 37 weeks' GA, females however, presented with a mature FHR startle response by 31 weeks' GA. The results indicate that there are different rates of maturation in the male and female fetuses that may have implications for sex-specific programming influences.

The Typical Developmental Trajectory of Social and Executive Functions in Late Adolescence and Early Adulthood

ERIC Educational Resources Information Center

Taylor, Sophie Jane; Barker, Lynne Ann; Heavey, Lisa; McHale, Sue

2013-01-01

Executive functions and social cognition develop through childhood into adolescence and early adulthood and are important for adaptive goal-oriented behavior (Apperly, Samson, & Humphreys, 2009; Blakemore & Choudhury, 2006). These functions are attributed to frontal networks known to undergo protracted maturation into early adulthood…

Autophagy proteins are not universally required for phagosome maturation.

PubMed

Cemma, Marija; Grinstein, Sergio; Brumell, John H

2016-09-01

Phagocytosis plays a central role in immunity and tissue homeostasis. After internalization of cargo into single-membrane phagosomes, these compartments undergo a maturation sequences that terminates in lysosome fusion and cargo degradation. Components of the autophagy pathway have recently been linked to phagosome maturation in a process called LC3-associated phagocytosis (LAP). In this process, autophagy machinery is thought to conjugate LC3 directly onto the phagosomal membrane to promote lysosome fusion. However, a recent study has suggested that ATG proteins may in fact impair phagosome maturation to promote antigen presentation. Here, we examined the impact of ATG proteins on phagosome maturation in murine cells using FCGR2A/FcγR-dependent phagocytosis as a model. We show that phagosome maturation is not affected in Atg5-deficient mouse embryonic fibroblasts, or in Atg5- or Atg7-deficient bone marrow-derived macrophages using standard assays of phagosome maturation. We propose that ATG proteins may be required for phagosome maturation under some conditions, but are not universally required for this process.

Life History Attributes of Asian Carps in the Upper Mississippi River System

DTIC Science & Technology

2007-05-01

Mature ovary of a female silver carp. Each small white spherical structure is a mature egg 4 ERDC/TN ANSRP-07-1 May 2007 Silver carp in the...weight/fish weight), and fecundity (number of eggs per female ) of each silver and bighead carp were quantified. Diets of silver carp from the MMR also...through November, with gonads ranging from 1 to 13 percent of body weight. Females with mature ovaries (Figure 3) were present as early as age 2 years

31 CFR Appendix B to Part 344 - Formula for Determining Redemption Value for Securities Subscribed for and Early-Redeemed On or...

Code of Federal Regulations, 2012 CFR

2012-07-01

... redemption at a premium. (i) Assume that an $800,000 2-year note is issued on December 10, 1996, to mature on... to be 8.00%: (i) Assume that an $800,000 2-year note is issued on December 10, 1996, to mature on... security is issued on December 5, 1996, to mature in 151 days on May 5, 1997. Interest at a rate of 5% is...

31 CFR Appendix B to Part 344 - Formula for Determining Redemption Value for Securities Subscribed for and Early-Redeemed On or...

Code of Federal Regulations, 2014 CFR

2014-07-01

... redemption at a premium. (i) Assume that an $800,000 2-year note is issued on December 10, 1996, to mature on... to be 8.00%: (i) Assume that an $800,000 2-year note is issued on December 10, 1996, to mature on... security is issued on December 5, 1996, to mature in 151 days on May 5, 1997. Interest at a rate of 5% is...

Basketball Performance Is Related to Maturity and Relative Age in Elite Adolescent Players.

PubMed

Torres-Unda, Jon; Zarrazquin, Idoia; Gravina, Leyre; Zubero, Jaime; Seco, Jesús; Gil, Susana M; Gil, Javier; Irazusta, Jon

2016-05-01

During a national championship, the anthropometric, physiological, and maturation characteristics of 13- to 14-year-old players of elite basketball teams and their association with sport performance were analyzed. Body parameters (weight, height, skinfold thicknesses, and lengths) were measured and physiological capacities assessed by sprint (20 m) and jump tests (i.e., countermovement jump with arm swing). Chronological age (CA) and maturity offset (years from age at peak height velocity; YAPHV) were calculated, and then predicted age at peak height velocity, as the difference between CA and YAPHV. Game performance was assessed with point averages and the performance index rating (PIR). The birth-date distribution of players was biased, those born early in the selection year outnumbering those born later. Anthropometric analysis indicated that players who performed better had longer body lengths. Physiological testing showed that semi-finalists had better sprint performance than quarter-finalists and those players with greater jump capacity scored more points. Early maturation and advanced maturity status were also associated with better PIR and scored points per game. Multiple blockwise regression analysis showed that, among the factors analyzed, YAPHV was the best predictor of basketball performance. In conclusion, around puberty, physical and physiological parameters associated with maturity and CA are important in determining the success of elite basketball players. Consequently, boys who are born in the second half of the year and/or late maturing tend to be marginalized or totally excluded, and not given the chance to play under equal conditions; their careers may then be held back by the relative disadvantage associated with inexperience.

Amorphous silica maturation in chemically weathered clastic sediments

NASA Astrophysics Data System (ADS)

Liesegang, Moritz; Milke, Ralf; Berthold, Christoph

2018-03-01

A detailed understanding of silica postdepositional transformation mechanisms is fundamental for its use as a palaeobiologic and palaeoenvironmental archive. Amorphous silica (opal-A) is an important biomineral, an alteration product of silicate rocks on the surface of Earth and Mars, and a precursor material for stable silica phases. During diagenesis, amorphous silica gradually and gradationally transforms to opal-CT, opal-C, and eventually quartz. Here we demonstrate the early-stage maturation of several million year old opal-A from deeply weathered Early Cretaceous and Ordovician sedimentary rocks of the Great Artesian Basin (central Australia). X-ray diffraction, scanning electron microscopy, and electron probe microanalyses show that the mineralogical maturation of the nanosphere material is decoupled from its chemical properties and begins significantly earlier than micromorphology suggests. Non-destructive and locally highly resolved X-ray microdiffraction (μ-XRD2) reveals an almost linear positive correlation between the main peak position (3.97 to 4.06 Å) and a new asymmetry parameter, AP. Heating experiments and calculated diffractograms indicate that nucleation and growth of tridymite-rich nanodomains induce systematic peak shifts and symmetry variations in diffraction patterns of morphologically juvenile opal-A. Our results show that the asymmetry parameter traces the early-stage maturation of amorphous silica, and that the mineralogical opal-A/CT stage extends to smaller d-spacings and larger FWHM values than previously suggested.

The autism associated MET receptor tyrosine kinase engages early neuronal growth mechanism and controls glutamatergic circuits development in the forebrain

PubMed Central

Peng, Yun; Lu, Zhongming; Li, Guohui; Piechowicz, Mariel; Anderson, Miranda; Uddin, Yasin; Wu, Jie; Qiu, Shenfeng

2015-01-01

The human MET gene imparts a replicated risk for autism spectrum disorder (ASD), and is implicated in the structural and functional integrity of brain. MET encodes a receptor tyrosine kinase, MET, which plays a pleiotropic role in embryogenesis and modifies a large number of neurodevelopmental events. Very little is known, however, on how MET signaling engages distinct cellular events to collectively affect brain development in ASD-relevant disease domains. Here, we show that MET protein expression is dynamically regulated and compartmentalized in developing neurons. MET is heavily expressed in neuronal growth cones at early developmental stages and its activation engages small GTPase Cdc42 to promote neuronal growth, dendritic arborization, and spine formation. Genetic ablation of MET signaling in mouse dorsal pallium leads to altered neuronal morphology indicative of early functional maturation. In contrast, prolonged activation of MET represses the formation and functional maturation of glutamatergic synapses. Moreover, manipulating MET signaling levels in vivo in the developing prefrontal projection neurons disrupts the local circuit connectivity made onto these neurons. Therefore, normal time-delimited MET signaling is critical in regulating the timing of neuronal growth, glutamatergic synapse maturation and cortical circuit function. Dysregulated MET signaling may lead to pathological changes in forebrain maturation and connectivity, and thus contribute to the emergence of neurological symptoms associated with ASD. PMID:26728565

Consonant and Vowel Processing in Word Form Segmentation: An Infant ERP Study.

PubMed

Von Holzen, Katie; Nishibayashi, Leo-Lyuki; Nazzi, Thierry

2018-01-31

Segmentation skill and the preferential processing of consonants (C-bias) develop during the second half of the first year of life and it has been proposed that these facilitate language acquisition. We used Event-related brain potentials (ERPs) to investigate the neural bases of early word form segmentation, and of the early processing of onset consonants, medial vowels, and coda consonants, exploring how differences in these early skills might be related to later language outcomes. Our results with French-learning eight-month-old infants primarily support previous studies that found that the word familiarity effect in segmentation is developing from a positive to a negative polarity at this age. Although as a group infants exhibited an anterior-localized negative effect, inspection of individual results revealed that a majority of infants showed a negative-going response (Negative Responders), while a minority showed a positive-going response (Positive Responders). Furthermore, all infants demonstrated sensitivity to onset consonant mispronunciations, while Negative Responders demonstrated a lack of sensitivity to vowel mispronunciations, a developmental pattern similar to previous literature. Responses to coda consonant mispronunciations revealed neither sensitivity nor lack of sensitivity. We found that infants showing a more mature, negative response to newly segmented words compared to control words (evaluating segmentation skill) and mispronunciations (evaluating phonological processing) at test also had greater growth in word production over the second year of life than infants showing a more positive response. These results establish a relationship between early segmentation skills and phonological processing (not modulated by the type of mispronunciation) and later lexical skills.

Managing expectations when publishing tools and methods for computational proteomics.

PubMed

Martens, Lennart; Kohlbacher, Oliver; Weintraub, Susan T

2015-05-01

Computational tools are pivotal in proteomics because they are crucial for identification, quantification, and statistical assessment of data. The gateway to finding the best choice of a tool or approach for a particular problem is frequently journal articles, yet there is often an overwhelming variety of options that makes it hard to decide on the best solution. This is particularly difficult for nonexperts in bioinformatics. The maturity, reliability, and performance of tools can vary widely because publications may appear at different stages of development. A novel idea might merit early publication despite only offering proof-of-principle, while it may take years before a tool can be considered mature, and by that time it might be difficult for a new publication to be accepted because of a perceived lack of novelty. After discussions with members of the computational mass spectrometry community, we describe here proposed recommendations for organization of informatics manuscripts as a way to set the expectations of readers (and reviewers) through three different manuscript types that are based on existing journal designations. Brief Communications are short reports describing novel computational approaches where the implementation is not necessarily production-ready. Research Articles present both a novel idea and mature implementation that has been suitably benchmarked. Application Notes focus on a mature and tested tool or concept and need not be novel but should offer advancement from improved quality, ease of use, and/or implementation. Organizing computational proteomics contributions into these three manuscript types will facilitate the review process and will also enable readers to identify the maturity and applicability of the tool for their own workflows.

Seafood-Processing Sludge Composting: Changes to Microbial Communities and Physico-Chemical Parameters of Static Treatment versus for Turning during the Maturation Stage

PubMed Central

Alves, David; Mato, Salustiano

2016-01-01

In general, in composting facilities the active, or intensive, stage of the process is done separately from the maturation stage, using a specific technology and time. The pre-composted material to be matured can contain enough biodegradable substrates to cause microbial proliferation, which in turn can cause temperatures to increase. Therefore, not controlling the maturation period during waste management at an industrial level can result in undesired outcomes. The main hypothesis of this study is that controlling the maturation stage through turning provides one with an optimized process when compared to the static approach. The waste used was sludge from a seafood-processing plant, mixed with shredded wood (1:2, v/v). The composting system consists of an intensive stage in a 600L static reactor, followed by maturation in triplicate in 200L boxes for 112 days. Two tests were carried out with the same process in reactor and different treatments in boxes: static maturation and turning during maturation when the temperature went above 55°C. PLFAs, organic matter, pH, electrical conductivity, forms of nitrogen and carbon, hydrolytic enzymes and respiratory activity were periodically measured. Turning significantly increased the duration of the thermophilic phase and consequently increased the organic-matter degradation. PCA differentiated significantly the two treatments in function of tracking parameters, especially pH, total carbon, forms of nitrogen and C/N ratio. So, stability and maturity optimum values for compost were achieved in less time with turnings. Whereas turning resulted in microbial-group stabilization and a low mono/sat ratio, static treatment produced greater variability in microbial groups and a high mono/sat ratio, the presence of more degradable substrates causes changes in microbial communities and their study during maturation gives an approach of the state of organic-matter degradation. Obtaining quality compost and optimizing the composting process requires using turning as a control mechanism during maturation. PMID:28002444

Representational Constraints on the Development of Memory and Metamemory: A Developmental-Representational Theory

ERIC Educational Resources Information Center

Ceci, Stephen J.; Fitneva, Stanka A.; Williams, Wendy M.

2010-01-01

Traditional accounts of memory development suggest that maturation of prefrontal cortex (PFC) enables efficient metamemory, which enhances memory. An alternative theory is described, in which changes in early memory and metamemory are mediated by representational changes, independent of PFC maturation. In a pilot study and Experiment 1, younger…

Polyamines in embryogenic cultures of Norway spruce (Picea abies) and red spruce (Picea rubens)

Treesearch

Rakesh Minocha; Haarald Kvaalen; Subhash C. Minocha; Stephanie Long

1993-01-01

Embryogenic cultures of red spruce (Picea rubens Sarg.) and Norway spruce (Picea abies (L.) Karst.) were initiated from dissected mature zygotic embryos. The tissues were grown on either proliferation medium or maturation medium. On proliferation medium, the embryogenic tissue continued to produce early stage somatic embryos (...

Effects from early planting of late-maturing sunflowers on damage from primary insect pests in the United States

USDA-ARS?s Scientific Manuscript database

Delayed planting is recommended to reduce damage from sunflower insect pests in the United States, including the sunflower moth, Homoeosoma electellum (Hulst) and banded sunflower moth, Cochylis hospes Walsingham. However, in some locations, planting earlier or growing later-maturing hybrids could i...

31 CFR Appendix A to Part 344 - Early Redemption Market Charge Formulas and Examples for Subscriptions From December 28, 1976...

Code of Federal Regulations, 2014 CFR

2014-07-01

... that a $600,000 note is issued on July 1, 1985, to mature on July 1, 1995. Interest is payable at a... that a $50,000 certificate of indebtedness is issued on March 1, 1987, to mature on November 1, 1987...

31 CFR Appendix A to Part 344 - Early Redemption Market Charge Formulas and Examples for Subscriptions From December 28, 1976...

Code of Federal Regulations, 2013 CFR

2013-07-01

... that a $600,000 note is issued on July 1, 1985, to mature on July 1, 1995. Interest is payable at a... that a $50,000 certificate of indebtedness is issued on March 1, 1987, to mature on November 1, 1987...

31 CFR Appendix A to Part 344 - Early Redemption Market Charge Formulas and Examples for Subscriptions From December 28, 1976...

Code of Federal Regulations, 2012 CFR

2012-07-01

... that a $600,000 note is issued on July 1, 1985, to mature on July 1, 1995. Interest is payable at a... that a $50,000 certificate of indebtedness is issued on March 1, 1987, to mature on November 1, 1987...

Development of sunflower oil and composition with respect to seed moisture and physiological maturity

USDA-ARS?s Scientific Manuscript database

Desiccants/harvest aids are becoming more commonly used to hasten sunflower harvest. The current recommendation is to apply a desiccant (e.g., glyphosate and paraquat) at 35% or less seed moisture at physiological maturity (PM). Desiccating as early as possible without sacrificing yield may be a des...

Body Structure and Physical Self-Concept in Early Adolescence

ERIC Educational Resources Information Center

Zsakai, Annamaria; Karkus, Zsolt; Utczas, Katinka; Bodzsar, Eva B.

2017-01-01

In adolescence, the complexity of human ontogenesis embraces biological growth and maturation as well as mental, affective, and cognitive progress, and adaptation to the requirements of society. To accept our morphological constellation as part of our gender may prove a problem even to a child of average rate of maturation. The main purposes of…

Early Antibody Lineage Diversification and Independent Limb Maturation Lead to Broad HIV-1 Neutralization Targeting the Env High-Mannose Patch.

PubMed

MacLeod, Daniel T; Choi, Nancy M; Briney, Bryan; Garces, Fernando; Ver, Lorena S; Landais, Elise; Murrell, Ben; Wrin, Terri; Kilembe, William; Liang, Chi-Hui; Ramos, Alejandra; Bian, Chaoran B; Wickramasinghe, Lalinda; Kong, Leopold; Eren, Kemal; Wu, Chung-Yi; Wong, Chi-Huey; Kosakovsky Pond, Sergei L; Wilson, Ian A; Burton, Dennis R; Poignard, Pascal

2016-05-17

The high-mannose patch on HIV Env is a preferred target for broadly neutralizing antibodies (bnAbs), but to date, no vaccination regimen has elicited bnAbs against this region. Here, we present the development of a bnAb lineage targeting the high-mannose patch in an HIV-1 subtype-C-infected donor from sub-Saharan Africa. The Abs first acquired autologous neutralization, then gradually matured to achieve breadth. One Ab neutralized >47% of HIV-1 strains with only ∼11% somatic hypermutation and no insertions or deletions. By sequencing autologous env, we determined key residues that triggered the lineage and participated in Ab-Env coevolution. Next-generation sequencing of the Ab repertoire showed an early expansive diversification of the lineage followed by independent maturation of individual limbs, several of them developing notable breadth and potency. Overall, the findings are encouraging from a vaccine standpoint and suggest immunization strategies mimicking the evolution of the entire high-mannose patch and promoting maturation of multiple diverse Ab pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

A conceptual framework and classification of capability areas for business process maturity

NASA Astrophysics Data System (ADS)

Van Looy, Amy; De Backer, Manu; Poels, Geert

2014-03-01

The article elaborates on business process maturity, which indicates how well an organisation can perform based on its business processes, i.e. on its way of working. This topic is of paramount importance for managers who try to excel in today's competitive world. Hence, business process maturity is an emerging research field. However, no consensus exists on the capability areas (or skills) needed to excel. Moreover, their theoretical foundation and synergies with other fields are frequently neglected. To overcome this gap, our study presents a conceptual framework with six main capability areas and 17 sub areas. It draws on theories regarding the traditional business process lifecycle, which are supplemented by recognised organisation management theories. The comprehensiveness of this framework is validated by mapping 69 business process maturity models (BPMMs) to the identified capability areas, based on content analysis. Nonetheless, as a consensus neither exists among the collected BPMMs, a classification of different maturity types is proposed, based on cluster analysis and discriminant analysis. Consequently, the findings contribute to the grounding of business process literature. Possible future avenues are evaluating existing BPMMs, directing new BPMMs or investigating which combinations of capability areas (i.e. maturity types) contribute more to performance than others.

Does implied volatility of currency futures option imply volatility of exchange rates?

NASA Astrophysics Data System (ADS)

Wang, Alan T.

2007-02-01

By investigating currency futures options, this paper provides an alternative economic implication for the result reported by Stein [Overreactions in the options market, Journal of Finance 44 (1989) 1011-1023] that long-maturity options tend to overreact to changes in the implied volatility of short-maturity options. When a GARCH process is assumed for exchange rates, a continuous-time relationship is developed. We provide evidence that implied volatilities may not be the simple average of future expected volatilities. By comparing the term-structure relationship of implied volatilities with the process of the underlying exchange rates, we find that long-maturity options are more consistent with the exchange rates process. In sum, short-maturity options overreact to the dynamics of underlying assets rather than long-maturity options overreacting to short-maturity options.

Genetic architecture of threshold reaction norms for male alternative reproductive tactics in Atlantic salmon (Salmo salar L.)

PubMed Central

Lepais, Olivier; Manicki, Aurélie; Glise, Stéphane; Buoro, Mathieu; Bardonnet, Agnès

2017-01-01

Alternative mating tactics have important ecological and evolutionary implications and are determined by complex interactions between environmental and genetic factors. Here, we study the genetic effect and architecture of the variability in reproductive tactics among Atlantic salmon males which can either mature sexually early in life in freshwater or more commonly only after completing a migration at sea. We applied the latent environmental threshold model (LETM), which provides a conceptual framework linking individual status to a threshold controlling the decision to develop alternative traits, in an innovative experimental design using a semi-natural river which allowed for ecologically relevant phenotypic expression. Early male parr maturation rates varied greatly across families (10 to 93%) which translated into 90% [64–100%] of the phenotypic variation explained by genetic variation. Three significant QTLs were found for the maturation status, however only one collocated with a highly significant QTL explaining 20.6% of the variability of the maturation threshold located on chromosome 25 and encompassing a locus previously shown to be linked to sea age at maturity in anadromous Atlantic salmon. These results provide new empirical illustration of the relevance of the LETM for a better understanding of alternative mating tactics evolution in natural populations. PMID:28281522

Neural competition as a developmental process: early hemispheric specialization for word processing delays specialization for face processing.

PubMed

Li, Su; Lee, Kang; Zhao, Jing; Yang, Zhi; He, Sheng; Weng, Xuchu

2013-04-01

Little is known about the impact of learning to read on early neural development for word processing and its collateral effects on neural development in non-word domains. Here, we examined the effect of early exposure to reading on neural responses to both word and face processing in preschool children with the use of the Event Related Potential (ERP) methodology. We specifically linked children's reading experience (indexed by their sight vocabulary) to two major neural markers: the amplitude differences between the left and right N170 on the bilateral posterior scalp sites and the hemispheric spectrum power differences in the γ band on the same scalp sites. The results showed that the left-lateralization of both the word N170 and the spectrum power in the γ band were significantly positively related to vocabulary. In contrast, vocabulary and the word left-lateralization both had a strong negative direct effect on the face right-lateralization. Also, vocabulary negatively correlated with the right-lateralized face spectrum power in the γ band even after the effects of age and the word spectrum power were partialled out. The present study provides direct evidence regarding the role of reading experience in the neural specialization of word and face processing above and beyond the effect of maturation. The present findings taken together suggest that the neural development of visual word processing competes with that of face processing before the process of neural specialization has been consolidated. Copyright © 2013 Elsevier Ltd. All rights reserved.

Detrimental Psychological Outcomes Associated with Early Pubertal Timing in Adolescent Girls

PubMed Central

Mendle, Jane; Turkheimer, Eric; Emery, Robert E.

2010-01-01

Though often discussed as though it were a discrete event, puberty comprises one segment of a larger developmental continuum and is notable for rapid transformation across a multitude of domains. Research suggests that an earlier rate of pubertal maturation in girls correlates with a number of detrimental outcomes compared with on-time or later maturation. The present review synthesizes the research on negative psychological sequelae of early pubertal timing in adolescent girls. Emphasis is on three theoretical perspectives by which precocious development is believed to affect the emergence of adverse outcomes: biological, psychosocial, and selection effects. PMID:20740062

History and utility of zeolite framework-type discovery from a data-science perspective

DOE PAGES

Zimmermann, Nils E. R.; Haranczyk, Maciej

2016-05-02

Mature applications such as fluid catalytic cracking and hydrocracking rely critically on early zeolite structures. With a data-driven approach, we find that the discovery of exceptional zeolite framework types around the new millennium was spurred by exciting new utilization routes. The promising processes have yet not been successfully implemented (“valley of death” effect), mainly because of the lack of thermal stability of the crystals. As a result, this foreshadows limited deployability of recent zeolite discoveries that were achieved by novel crystal synthesis routes.

Editorial: The effects of early trauma and deprivation on human development - from measuring cumulative risk to characterizing specific mechanisms.

PubMed

Zeanah, Charles H; Sonuga-Barke, Edmund J S

2016-10-01

Science is not a linear process of accumulating knowledge. To the contrary, progress in understanding is most likely to occur, especially in less 'mature' disciplines, when healthy debate between opposing points of view create a dialectic in which thesis and antithesis force a new synthesis. In developmental psychopathology, such tension between opposing schools of thought continue to play a vital role in driving discovery across a wide range of topics. © 2016 Association for Child and Adolescent Mental Health.

Morphogenesis and calcification of the statoconia in the chick (Gallus domesticus) embryo - Implications for future studies

NASA Technical Reports Server (NTRS)

Fermin, C. D.; Igarashi, M.

1985-01-01

The morphogenesis of the statoconia in the chick, Gallus domesticus, injected with a carbon anhydrase inhibitor is studied. The preparation of the embryo specimens for analysis is described. The early, middle, and late stages of embryonic development are examined. The data reveal that acetozolamide inhibits statoconia formation in the middle stage of development and the calcification process follows statoconia formation. The spatial relationship between the development of type 1 and type 2 hair cells and the appearance and maturation of the statoconia is investigated.

Top 10 Research Questions Related to Growth and Maturation of Relevance to Physical Activity, Performance, and Fitness

ERIC Educational Resources Information Center

Malina, Robert M.

2014-01-01

Growth, maturation, and development dominate the daily lives of children and adolescents for approximately the first 2 decades of life. Growth and maturation are biological processes, while development is largely a behavioral process. The 3 processes occur simultaneously and interact. They can be influenced by physical activity and also can…

7 CFR 51.1313 - Mature.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Mature. 51.1313 Section 51.1313 Agriculture... Standards for Winter Pears 1 Definitions § 51.1313 Mature. (a) Mature means that the pear has reached the stage of maturity which will insure the proper completion of the ripening process. (b) Before a mature...

7 CFR 51.1313 - Mature.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Mature. 51.1313 Section 51.1313 Agriculture... Standards for Winter Pears 1 Definitions § 51.1313 Mature. (a) Mature means that the pear has reached the stage of maturity which will insure the proper completion of the ripening process. (b) Before a mature...

7 CFR 51.1313 - Mature.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Mature. 51.1313 Section 51.1313 Agriculture... Standards for Winter Pears 1 Definitions § 51.1313 Mature. (a) Mature means that the pear has reached the stage of maturity which will insure the proper completion of the ripening process. (b) Before a mature...

Discrimination of single features and conjunctions by children.

PubMed

Taylor, M J; Chevalier, H; Lobaugh, N J

2003-12-01

Stimuli that are discriminated by a conjunction of features can show more rapid early processing in adults. To determine how this facilitation effect develops, the processing of visual features and their conjunction was examined in 7-12-year-old children. The children completed a series of tasks in which they made a target-non-target judgement as a function of shape only, colour only or shape and colour features, while event-related potentials were recorded. To assess early stages of feature processing the posteriorly distributed P1 and N1 were analysed. Attentional effects were seen for both components. P1 had a shorter latency and P1 and N1 had larger amplitudes to targets than non-targets. Task effects were driven by the conjunction task. P1 amplitude was largest, while N1 amplitude was smallest for the conjunction targets. In contrast to larger left-sided N1 in adults, N1 had a symmetrical distribution in the children. N1 latency was shortest for the conjunction targets in the 9-10-year olds and 11-12-year olds, demonstrating facilitation in children, but which continued to develop over the pre-teen years. These data underline the sensitivity of early stages of processing to both top-down modulations and the parallel binding of non-spatial features in young children. Furthermore, facilitation effects, increased speed of processing when features need to be conjoined, mature in mid-childhood, arguing against a hierarchical model of visual processing, and supporting a rapid, integrated facilitative model.

Thermal maturation history of the Wilcox group (Paleocene-Eocene), Texas: Results of regional-scale multi-1D modeling

USGS Publications Warehouse

Rowan, E.L.; Warwick, Peter D.; Pitman, Janet K.; Kennan, Lorcan; Pindell, James; Rosen, Norman C.

2007-01-01

The thermal maturation history of the Paleocene-Eocene Wilcox Group has been reconstructed based on burial history models of 53 wells in the Texas coastal plain. This modeling study has been conducted in conjunction with a geologically based assessment of the oil and gas resources in Cenozoic strata of the Gulf of Mexico coastal plain and state waters. In the onshore Texas coastal plain, coals and organic-rich shales, predominantly of terrestrial origin, within the Wilcox Group are the primary source of oil (Wenger et al., 1994) as well as a source of gas. The Wilcox, however, is modeled as a single unit, without subdivision into source rock and non-source rock intervals.Generation of oil from Type III kerogen within the Wilcox Group is modeled using hydrous pyrolysis reaction kinetic parameters (Lewan, M.D., written communication, 2006). Gas generation from Type III kerogen is represented using calculated Ro values. The models are calibrated with bottom hole temperature (BHT), and vitrinite reflectance (Ro %) data for the Wilcox Group. Ro data from near-coastal sites have been selected to minimize the possible effects of uplift and erosion and then composited to give a regional Rodepth trend.Model calculations for the study area, the onshore Texas coastal plain, indicate that downdip portions of the basal Wilcox had reached sufficient thermal maturity to generate hydrocarbons by early Eocene (~50 Ma). This relatively early maturation is explained by rapid sediment accumulation in the early Tertiary combined with the reaction kinetic parameters used in the models. Thermal maturation increases through time with increasing burial depth and temperature, gradually moving the maturation front updip. At present day, hydrocarbon generation is complete in the downdip Wilcox within the study area but is currently ongoing in the updip portions of the formation.

Validation of a noninvasive maturity estimate relative to skeletal age in youth football players.

PubMed

Malina, Robert M; Dompier, Thomas P; Powell, John W; Barron, Mary J; Moore, Marguerite T

2007-09-01

To validate a non-invasive measure of biological maturity (percentage of predicted mature height at a given age) with an established indicator of maturity [skeletal age (SA)] in youth American football players. Cross-sectional. Two communities in central Michigan. 143 youth football players 9.27 to 14.24 years. Height and weight were measured, and hand-wrist radiographs were taken. SA assessed with the Fels method was the criterion measure of maturity status. Chronological age (CA), height, and weight of the player and midparent height were used to predict mature height; current height of the player was expressed as a percentage of his predicted mature height as a noninvasive estimate of biological maturity status. Boys' maturation was classified as late, on time, or early maturing on the basis of the difference between SA and CA and of present height expressed as a percentage of predicted mature height. Kappa coefficients and Spearman rank-order correlations were calculated. Characteristics of players concordant and discordant for maturity classification with SA and percentage of predicted mature height were compared with MANCOVA. Concordance between methods of maturity classification was 62%. The Kappa coefficient, 0.46 (95% CI 0.19 to 0.59) and Spearman rank-order correlation, rs = 0.52 (P < 0.001) were moderate. Players discordant for maturity status varied in midparent height and percentage of predicted mature height, but not in predicted mature height. Percentage of predicted mature height is a reasonably valid estimate of biological maturity status in this sample of youth football players.

Sequential Notch activation regulates ventricular chamber development

PubMed Central

D'Amato, Gaetano; Luxán, Guillermo; del Monte-Nieto, Gonzalo; Martínez-Poveda, Beatriz; Torroja, Carlos; Walter, Wencke; Bochter, Matthew S.; Benedito, Rui; Cole, Susan; Martinez, Fernando; Hadjantonakis, Anna-Katerina; Uemura, Akiyoshi; Jiménez-Borreguero, Luis J.; de la Pompa, José Luis

2016-01-01

Ventricular chambers are essential for the rhythmic contraction and relaxation occurring in every heartbeat throughout life. Congenital abnormalities in ventricular chamber formation cause severe human heart defects. How the early trabecular meshwork of myocardial fibres forms and subsequently develops into mature chambers is poorly understood. We show that Notch signalling first connects chamber endocardium and myocardium to sustain trabeculation, and later coordinates ventricular patterning and compaction with coronary vessel development to generate the mature chamber, through a temporal sequence of ligand signalling determined by the glycosyltransferase manic fringe (MFng). Early endocardial expression of MFng promotes Dll4–Notch1 signalling, which induces trabeculation in the developing ventricle. Ventricular maturation and compaction require MFng and Dll4 downregulation in the endocardium, which allows myocardial Jag1 and Jag2 signalling to Notch1 in this tissue. Perturbation of this signalling equilibrium severely disrupts heart chamber formation. Our results open a new research avenue into the pathogenesis of cardiomyopathies. PMID:26641715

Thermal maturation and petroleum source rocks in Forest City and Salina basins, mid-continent, U. S. A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Newell, K.D.; Watney, W.L.; Hatch, J.R.

1986-05-01

Shales in the Middle Ordovician Simpson Group are probably the source rocks for a geochemically distinct group of lower pristane and low phytane oils produced along the axis of the Forest City basin, a shallow cratonic Paleozoic basin. These oils, termed Ordovician-type oils, occur in some fields in the southern portion of the adjacent Salina basin. Maturation modeling by time-temperature index (TTI) calculations indicate that maturation of both basins was minimal during the early Paleozoic. The rate of maturation significantly increased during the Pennsylvanian because of rapid regional subsidence in response to the downwarping of the nearby Anadarko basin. Whenmore » estimated thicknesses of eroded Pennsylvanian, Permian, and Cretaceous strata are considered, both basins remain relatively shallow, with maximum basement burial probably not exceeding 2 km. According to maturation modeling and regional structure mapping, the axes of both basins should contain Simpson rocks in the early stages of oil generation. The probability of finding commercial accumulations of Ordovician-type oil along the northwest-southeast trending axis of the Salina basin will decrease in a northwestward direction because of (1) westward thinning of the Simpson Group, and (2) lesser maturation due to lower geothermal gradients and shallower paleoburial depths. The optimum localities for finding fields of Ordovician-type oil in the southern Salina basin will be in down-plunge closures on anticlines that have drainage areas near the basin axis.« less

Expression of the Nitrate Transporter Gene OsNRT1.1A/OsNPF6.3 Confers High Yield and Early Maturation in Rice.

PubMed

Wang, Wei; Hu, Bin; Yuan, Dingyang; Liu, Yongqiang; Che, Ronghui; Hu, Yingchun; Ou, Shujun; Liu, Yongxin; Zhang, Zhihua; Wang, Hongru; Li, Hua; Jiang, Zhimin; Zhang, Zhengli; Gao, Xiaokai; Qiu, Yahong; Meng, Xiangbing; Liu, Yongxin; Bai, Yang; Liang, Yan; Wang, Yiqin; Zhang, Lianhe; Li, Legong; Sodmergen; Jing, Haichun; Li, Jiayang; Chu, Chengcai

2018-03-01

Nitrogen (N) is a major driving force for crop yield improvement, but application of high levels of N delays flowering, prolonging maturation and thus increasing the risk of yield losses. Therefore, traits that enable utilization of high levels of N without delaying maturation will be highly desirable for crop breeding. Here, we show that OsNRT1.1A (OsNPF6.3), a member of the rice ( Oryza sativa ) nitrate transporter 1/peptide transporter family, is involved in regulating N utilization and flowering, providing a target to produce high yield and early maturation simultaneously. OsNRT.1A has functionally diverged from previously reported NRT1.1 genes in plants and functions in upregulating the expression of N utilization-related genes not only for nitrate but also for ammonium, as well as flowering-related genes. Relative to the wild type, osnrt1.1a mutants exhibited reduced N utilization and late flowering. By contrast, overexpression of OsNRT1.1A in rice greatly improved N utilization and grain yield, and maturation time was also significantly shortened. These effects were further confirmed in different rice backgrounds and also in Arabidopsis thaliana Our study paves a path for the use of a single gene to dramatically increase yield and shorten maturation time for crops, outcomes that promise to substantially increase world food security. © 2018 American Society of Plant Biologists. All rights reserved.

Expression of the Nitrate Transporter Gene OsNRT1.1A/OsNPF6.3 Confers High Yield and Early Maturation in Rice[OPEN

PubMed Central

Wang, Wei; Hu, Bin; Liu, Yongqiang; Che, Ronghui; Hu, Yingchun; Zhang, Zhihua; Wang, Hongru; Li, Hua; Jiang, Zhimin; Zhang, Zhengli; Gao, Xiaokai; Qiu, Yahong; Meng, Xiangbing; Liu, Yongxin; Bai, Yang; Liang, Yan; Wang, Yiqin; Zhang, Lianhe; Li, Legong; Sodmergen; Jing, Haichun

2018-01-01

Nitrogen (N) is a major driving force for crop yield improvement, but application of high levels of N delays flowering, prolonging maturation and thus increasing the risk of yield losses. Therefore, traits that enable utilization of high levels of N without delaying maturation will be highly desirable for crop breeding. Here, we show that OsNRT1.1A (OsNPF6.3), a member of the rice (Oryza sativa) nitrate transporter 1/peptide transporter family, is involved in regulating N utilization and flowering, providing a target to produce high yield and early maturation simultaneously. OsNRT.1A has functionally diverged from previously reported NRT1.1 genes in plants and functions in upregulating the expression of N utilization-related genes not only for nitrate but also for ammonium, as well as flowering-related genes. Relative to the wild type, osnrt1.1a mutants exhibited reduced N utilization and late flowering. By contrast, overexpression of OsNRT1.1A in rice greatly improved N utilization and grain yield, and maturation time was also significantly shortened. These effects were further confirmed in different rice backgrounds and also in Arabidopsis thaliana. Our study paves a path for the use of a single gene to dramatically increase yield and shorten maturation time for crops, outcomes that promise to substantially increase world food security. PMID:29475937

Oocyte maturation in the sloth's giant tick Amblyomma varium (Acari: Ixodidae) in an ecological context.

PubMed

Sanches, Gustavo S; André, Marcos R; do Prado, Angelo P; Allegretti, Silmara M; Remedio, Rafael N; Nunes, Pablo H; Machado, Rosangela Z; Bechara, Gervásio H; Camargo-Mathias, Maria I

2014-12-01

The sloth's giant tick Amblyomma varium Koch, which is a neotropical species that inhabits tropical rainforests, is the largest tick reported to date. The adult stage of this tick parasitizes mammals from the families Bradypodidae and Magalonychidae (Xenarthra) nearly exclusively. This study aimed to describe morphological and histological features of the reproductive system and the oocyte maturation process of this tick species. The ovary of A. varium is a long single tubular organ that is horseshoe-shaped, winding and arranged in the posterior part of the body. Two oviducts are connected to the ovary on each side; these thicken at certain region forming the uterus (common oviduct), followed by a muscular connecting tube, vagina and genital aperture. A large number of oocytes at different stages of development are attached to the ovary wall by the pedicel, as they reach maturity they are released into the ovary lumen and from there to the genital aperture. These oocytes develop simultaneously and asynchronically along the ovary. Amblyomma varium oocytes were classified into five development stages (i.e., I-V), and specific characteristics were observed; the processes of yolk and chorion deposition begin early in oocytes stage II, and oocytes V exhibit a very thick chorion and eggs of a large size. These characteristics are likely adaptations that enhance the survival and the reproductive success of this extremely host-specific tick, which is limited to a particular environment.

Biological embedding: evaluation and analysis of an emerging concept for nursing scholarship.

PubMed

Nist, Marliese Dion

2017-02-01

The purpose of this paper was to report the analysis of the concept of biological embedding. Research that incorporates a life course perspective is becoming increasingly prominent in the health sciences. Biological embedding is a central concept in life course theory and may be important for nursing theories to enhance our understanding of health states in individuals and populations. Before the concept of biological embedding can be used in nursing theory and research, an analysis of the concept is required to advance it towards full maturity. Concept analysis. PubMed, CINAHL and PsycINFO were searched for publications using the term 'biological embedding' or 'biological programming' and published through 2015. An evaluation of the concept was first conducted to determine the concept's level of maturity and was followed by a concept comparison, using the methods for concept evaluation and comparison described by Morse. A consistent definition of biological embedding - the process by which early life experience alters biological processes to affect adult health outcomes - was found throughout the literature. The concept has been used in several theories that describe the mechanisms through which biological embedding might occur and highlight its role in the development of health trajectories. Biological embedding is a partially mature concept, requiring concept comparison with an overlapping concept - biological programming - to more clearly establish the boundaries of biological embedding. Biological embedding has significant potential for theory development and application in multiple academic disciplines, including nursing. © 2016 John Wiley & Sons Ltd.

Mycobacterial Nucleoside Diphosphate Kinase Blocks Phagosome Maturation in Murine Raw 264.7 Macrophages

PubMed Central

Sun, Jim; Wang, Xuetao; Lau, Alice; Liao, Ting-Yu Angela; Bucci, Cecilia; Hmama, Zakaria

2010-01-01

Background Microorganisms capable of surviving within macrophages are rare, but represent very successful pathogens. One of them is Mycobacterium tuberculosis (Mtb) whose resistance to early mechanisms of macrophage killing and failure of its phagosomes to fuse with lysosomes causes tuberculosis (TB) disease in humans. Thus, defining the mechanisms of phagosome maturation arrest and identifying mycobacterial factors responsible for it are key to rational design of novel drugs for the treatment of TB. Previous studies have shown that Mtb and the related vaccine strain, M. bovis bacille Calmette-Guérin (BCG), disrupt the normal function of host Rab5 and Rab7, two small GTPases that are instrumental in the control of phagosome fusion with early endosomes and late endosomes/lysosomes respectively. Methodology/Principal Findings Here we show that recombinant Mtb nucleoside diphosphate kinase (Ndk) exhibits GTPase activating protein (GAP) activity towards Rab5 and Rab7. Then, using a model of latex bead phagosomes, we demonstrated that Ndk inhibits phagosome maturation and fusion with lysosomes in murine RAW 264.7 macrophages. Maturation arrest of phagosomes containing Ndk-beads was associated with the inactivation of both Rab5 and Rab7 as evidenced by the lack of recruitment of their respective effectors EEA1 (early endosome antigen 1) and RILP (Rab7-interacting lysosomal protein). Consistent with these findings, macrophage infection with an Ndk knocked-down BCG strain resulted in increased fusion of its phagosome with lysosomes along with decreased survival of the mutant. Conclusion Our findings provide evidence in support of the hypothesis that mycobacterial Ndk is a putative virulence factor that inhibits phagosome maturation and promotes survival of mycobacteria within the macrophage. PMID:20098737

Critical period inhibition of NKCC1 rectifies synapse plasticity in the somatosensory cortex and restores adult tactile response maps in fragile X mice.

PubMed

He, Qionger; Arroyo, Erica D; Smukowski, Samuel N; Xu, Jian; Piochon, Claire; Savas, Jeffrey N; Portera-Cailliau, Carlos; Contractor, Anis

2018-04-27

Sensory perturbations in visual, auditory and tactile perception are core problems in fragile X syndrome (FXS). In the Fmr1 knockout mouse model of FXS, the maturation of synapses and circuits during critical period (CP) development in the somatosensory cortex is delayed, but it is unclear how this contributes to altered tactile sensory processing in the mature CNS. Here we demonstrate that inhibiting the juvenile chloride co-transporter NKCC1, which contributes to altered chloride homeostasis in developing cortical neurons of FXS mice, rectifies the chloride imbalance in layer IV somatosensory cortex neurons and corrects the development of thalamocortical excitatory synapses during the CP. Comparison of protein abundances demonstrated that NKCC1 inhibition during early development caused a broad remodeling of the proteome in the barrel cortex. In addition, the abnormally large size of whisker-evoked cortical maps in adult Fmr1 knockout mice was corrected by rectifying the chloride imbalance during the early CP. These data demonstrate that correcting the disrupted driving force through GABA A receptors during the CP in cortical neurons restores their synaptic development, has an unexpectedly large effect on differentially expressed proteins, and produces a long-lasting correction of somatosensory circuit function in FXS mice.

Evaluation of whole mount in situ hybridization as a tool for pathway-based toxicological research in early-life stage fathead minnows

EPA Science Inventory

Early-life stage fish can be more sensitive to chemical exposure than mature, adult fish. Therefore, defining adverse outcome pathways (AOPs) relevant to early-life stages is critical for linking perturbations of key events during fish development to potential adverse outcomes of...

Leveraging People-Related Maturity Issues for Achieving Higher Maturity and Capability Levels

NASA Astrophysics Data System (ADS)

Buglione, Luigi

During the past 20 years Maturity Models (MM) become a buzzword in the ICT world. Since the initial Crosby's idea in 1979, plenty of models have been created in the Software & Systems Engineering domains, addressing various perspectives. By analyzing the content of the Process Reference Models (PRM) in many of them, it can be noticed that people-related issues have little weight in the appraisals of the capabilities of organizations while in practice they are considered as significant contributors in traditional process and organizational performance appraisals, as stressed instead in well-known Performance Management models such as MBQA, EFQM and BSC. This paper proposes some ways for leveraging people-related maturity issues merging HR practices from several types of maturity models into the organizational Business Process Model (BPM) in order to achieve higher organizational maturity and capability levels.

Exploring the early steps of aggregation of amyloid-forming peptide KFFE

NASA Astrophysics Data System (ADS)

Wei, Guanghong; Mousseau, Normand; Derreumaux, Philippe

2004-11-01

It has been shown recently that even a tetrapeptide can form amyloid fibrils sharing all the characteristics of amyloid fibrils built from large proteins. Recent experimental studies also suggest that the toxicity observed in several neurodegenerative diseases, such as Alzheimer's disease and Creutzfeldt-Jakob disease, is not only related to the mature fibrils themselves, but also to the soluble oligomers formed early in the process of fibrillogenesis. This raises the interest in studying the early steps of the aggregation process. Although fibril formation follows the nucleation-condensation process, characterized by the presence of lag phase, the exact pathways remain to be determined. In this study, we used the activation-relaxation technique and a generic energy model to explore the process of self-assembly and the structures of the resulting aggregates of eight KFFE peptides. Our simulations show, starting from different states with a preformed antiparallel dimer, that eight chains can self-assemble to adopt, with various orientations, four possible distant oligomeric well-aligned structures of similar energy. Two of these structures show a double-layer β-sheet organization, in agreement with the structure of amyloid fibrils as observed by x-ray diffraction; another two are mixtures of dimers and trimers. Our results also suggest that octamers are likely to be below the critical size for nucleation of amyloid fibrils for small peptides.

Maturation of metabolic connectivity of the adolescent rat brain

PubMed Central

Choi, Hongyoon; Choi, Yoori; Kim, Kyu Wan; Kang, Hyejin; Hwang, Do Won; Kim, E Edmund; Chung, June-Key; Lee, Dong Soo

2015-01-01

Neuroimaging has been used to examine developmental changes of the brain. While PET studies revealed maturation-related changes, maturation of metabolic connectivity of the brain is not yet understood. Here, we show that rat brain metabolism is reconfigured to achieve long-distance connections with higher energy efficiency during maturation. Metabolism increased in anterior cerebrum and decreased in thalamus and cerebellum during maturation. When functional covariance patterns of PET images were examined, metabolic networks including default mode network (DMN) were extracted. Connectivity increased between the anterior and posterior parts of DMN and sensory-motor cortices during maturation. Energy efficiency, a ratio of connectivity strength to metabolism of a region, increased in medial prefrontal and retrosplenial cortices. Our data revealed that metabolic networks mature to increase metabolic connections and establish its efficiency between large-scale spatial components from childhood to early adulthood. Neurodevelopmental diseases might be understood by abnormal reconfiguration of metabolic connectivity and efficiency. DOI: http://dx.doi.org/10.7554/eLife.11571.001 PMID:26613413

Identical twins with mature cystic teratomas treated with laparoscopic surgery: Two case reports.

PubMed

Mabuchi, Yasushi; Ota, Nami; Kobayashi, Aya; Tanizaki, Yuko; Minami, Sawako; Ino, Kazuhiko

2017-02-01

Mature cystic teratomas are the most common among all ovarian neoplasms, representing 30-40% of the cases. However, to the best of our knowledge, there have been only two reports of mature cystic teratomas occurring in identical twins to date. We herein report a case of identical twins with mature cystic teratomas who were treated with laparoscopic surgery. A 32-year-old woman was referred to our hospital due to a tumor in the right ovary. The patient underwent laparoscopic resection of the ovarian tumor and the pathological diagnosis was benign mature cystic teratoma. Two years later, the identical twin of the abovementioned patient was referred to our hospital also due to a right ovarian tumor. The patient underwent laparoscopic resection of the ovarian tumor and the pathological diagnosis was benign mature cystic teratoma. Therefore, for early diagnosis, it may be important to consider the possibility of mature cystic teratoma in the identical twin of a patient, even in the absence of symptoms.

The impact of early repeated pain experiences on stress responsiveness and emotionality at maturity in rats.

PubMed

Page, Gayle G; Blakely, Wendy P; Kim, Miyong

2005-01-01

The intensive care necessary for premature newborns is characterized by multiple procedures, many of which are painful. Given emerging evidence that such early pain during this time of high brain plasticity may affect long-term neurodevelopmental and social-emotional functioning, this study explored the impact of early repeated pain on emotionality and stress responsivity at maturity. From birth through postnatal day 7, Fischer 344 pups underwent either paw needle prick every day versus every other day or daily paw touch, or were left unperturbed. Each paw received the designated perturbation once per day. At maturity, some animals underwent emotionality testing: either a 4-day series of open field exposures or a single elevated plus-maze (EPM) exposure. The paw prick groups exhibited less open field habituation and occupied the EPM open arms more. Two weeks later, all animals were either subjected to forced swim or not. At 1h post-swim, animals underwent either blood withdrawal for plasma corticosterone (CS) levels and ex vivo natural killer cell activity (NKCA) or were injected intravenously with radiolabeled NK-sensitive syngeneic MADB106 tumor cells and assessed for lung tumor retention. Sex was a major factor in the manifestation of perturbation-related differences in the biologic outcomes. Whereas postnatal pain differentially affected baseline tumor retention between males and females, only males exhibited perturbation-related differences in swim stress-induced increases in tumor retention and CS. Finally, male-female differences were evident in CS, NKCA, and tumor responses to swim stress. These findings suggest that early pain affects neurodevelopmental function in the mature organism; however, these relationships are complicated by sex differences, the postnatal pain schedule, and the outcome measured.

Bistability in cell signaling: How to make continuous processes discontinuous, and reversible processes irreversible

NASA Astrophysics Data System (ADS)

Ferrell, James E.; Xiong, Wen

2001-03-01

Xenopus oocyte maturation is an example of an all-or-none, irreversible cell fate induction process. In response to a submaximal concentration of the steroid hormone progesterone, a given oocyte may either mature or not mature, but it can exist in intermediate states only transiently. Moreover, once an oocyte has matured, it will remain arrested in the mature state even after the progesterone is removed. It has been hypothesized that the all-or-none character of oocyte maturation, and some aspects of the irreversibility of maturation, arise out of the bistability of the signal transduction system that triggers maturation. The bistability, in turn, is hypothesized to arise from the way the signal transducers are organized into a signaling circuit that includes positive feedback (which makes it so that the system cannot rest in intermediate states) and ultrasensitivity (which filters small stimuli out of the feedback loop, allowing the system to have a stable off-state). Here we review two simple graphical methods that are commonly used to analyze bistable systems, discuss the experimental evidence for bistability in oocyte maturation, and suggest that bistability may be a common means of producing all-or-none responses and a type of biochemical memory.

Multiple Memory Systems Are Unnecessary to Account for Infant Memory Development: An Ecological Model

ERIC Educational Resources Information Center

Rovee-Collier, Carolyn; Cuevas, Kimberly

2009-01-01

How the memory of adults evolves from the memory abilities of infants is a central problem in cognitive development. The popular solution holds that the multiple memory systems of adults mature at different rates during infancy. The "early-maturing system" (implicit or nondeclarative memory) functions automatically from birth, whereas the…

Maturation of Acorns of Cherrybark, Water, and Willow Oaks

Treesearch

F. T. Bonner

1974-01-01

Acorns of cherrybark, water, and willow oaks grew slowly but steadily in July and August and reached maximum size in September, when fats and carbohydrates, the major storage foods, accumulated rapidly. At physiological maturity in late October or early November, crude fat levels were 15 to 20 percent of seed dry weight and carbohydrates totaled 25 percent.

Yield response to planting date among soybean maturity groups for irrigated production in the US Midsouth

USDA-ARS?s Scientific Manuscript database

Planting date is one of the main factors affecting soybean (Glycine max L. (Merr.)) yield. Environmental conditions in the US Midsouth allow for planting dates from late March through early July, and maturity groups (MGs) ranging from 3 to 6. However, the complexity of the interaction among planting...

Condition varies with habitat choice in postbreeding forest birds

Treesearch

Scott H. Stoleson

2013-01-01

Many birds that are experiencing population declines require extensive tracts of mature forest habitat for breeding. Recent work suggests that at least some may shift their habitat use to early-successional areas after nesting but before migration. I used constant-effort mist netting in regenerating clearcuts (4-8 years postcut) and dense mature-forest understories to...

Mapping Subcortical Brain Maturation during Adolescence: Evidence of Hemisphere-and Sex-Specific Longitudinal Changes

ERIC Educational Resources Information Center

Dennison, Meg; Whittle, Sarah; Yücel, Murat; Vijayakumar, Nandita; Kline, Alexandria; Simmons, Julian; Allen, Nicholas B.

2013-01-01

Early to mid-adolescence is an important developmental period for subcortical brain maturation, but longitudinal studies of these neurodevelopmental changes are lacking. The present study acquired repeated magnetic resonance images from 60 adolescent subjects (28 female) at ages 12.5 and 16.5 years to map changes in subcortical structure volumes.…

Emerald ash borer biocontrol in ash saplings: The potential for early stage recovery of North American ash trees

Treesearch

Jian J. Duan; Leah S. Bauer; Roy G. Van Driesche

2017-01-01

In many parts of North America, ash (Fraxinus) stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees, saplings, basal sprouts, and seedlings. Without a soil seed bank for Fraxinus spp., tree recovery will require survival and maturation of these...

Emerald ash borer biocontrol in ash saplings: the potential for early stage recovery of North American ash

USDA-ARS?s Scientific Manuscript database

In many parts of North America, ash stands have been reduced by the emerald ash borer (Agrilus planipennis) invasion to a few surviving mature trees and young basal sprouts, saplings, and seedlings. Without a seed bank, ash tree recovery will require survival and maturation of these younger cohorts...

Continuity and Change in Poor Sleep from Childhood to Early Adolescence

PubMed Central

Pesonen, Anu-Katriina; Martikainen, Silja; Heinonen, Kati; Wehkalampi, Karoliina; Lahti, Jari; Kajantie, Eero; Räikkönen, Katri

2014-01-01

Study Objectives: We examined associations between pubertal maturation and sleep in early adolescence, at age 12 y, and continuity and change in actigraphy-based sleep and parent-reported sleep disorders from age 8 to 12 y. We also explored longitudinal associations between actigraph estimates of sleep and sleep disorders. Design: A cohort study of children born in 1998 and tested at ages 8 y (standard deviation [SD] = 0.3) and 12 y (SD = 0.5). Participants: A total of 348 children participated in cross-sectional analyses. We had longitudinal actigraphy data for 188 children and repeated parent reports of sleep disorders for 229 children. Measurements and Results: At age 8 y, participants wore actigraphs for 7.1 nights (SD = 1.2, range 3-14) on average and at age 12 y for 8.4 nights (SD = 1.7, range 3-11). Sleep disorders were parent-rated based on the Sleep Disturbance Scale for Children. Pubertal maturity was self-reported at age 12 y using the continuous Pubertal Development Scale and the picture-assisted categorical Tanner scales. Results: Significant mean-level changes toward shorter but higher quality sleep occurred over time. Sleep variables had low to high rank-order stability over time. Sleep disorders were highly stable from age 8 to 12 y. Actigraphy-based sleep and parent-rated sleep disorders showed no association either in cross-section or longitudinally. Pubertal maturation was not associated with worse sleep. Conclusions: Sleep in early adolescence can be anticipated from childhood sleep patterns and disorders, but is not associated with pubertal maturity. Although sleep duration becomes shorter, sleep quality may improve during early adolescence. Parent-rated sleep disorders are distinct from actigraph estimates of sleep. Citation: Pesonen AK; Martikainen S; Heinonen K; Wehkalampi K; Lahti J; Kajantie E; Räikkönen K. Continuity and change in poor sleep from childhood to early adolescence. SLEEP 2014;37(2):289-297. PMID:24497657

The short-time structural plasticity of dendritic spines is altered in a model of Rett syndrome.

PubMed

Landi, Silvia; Putignano, Elena; Boggio, Elena Maria; Giustetto, Maurizio; Pizzorusso, Tommaso; Ratto, Gian Michele

2011-01-01

The maturation of excitatory transmission comes about through a developmental period in which dendritic spines are highly motile and their number, form and size are rapidly changing. Surprisingly, although these processes are crucial for the formation of cortical circuitry, little is known about possible alterations of these processes in brain disease. By means of acute in vivo 2-photon imaging we show that the dynamic properties of dendritic spines of layer V cortical neurons are deeply affected in a mouse model of Rett syndrome (RTT) at a time around P25 when the neuronal phenotype of the disease is still mild. Then, we show that 24h after a subcutaneous injection of IGF-1 spine dynamics is restored. Our study demonstrates that spine dynamics in RTT mice is severely impaired early during development and suggest that treatments for RTT should be started very early in order to reestablish a normal period of spine plasticity.

FLASH is essential during early embryogenesis and cooperates with p73 to regulate histone gene transcription.

PubMed

De Cola, A; Bongiorno-Borbone, L; Bianchi, E; Barcaroli, D; Carletti, E; Knight, R A; Di Ilio, C; Melino, G; Sette, C; De Laurenzi, V

2012-02-02

Replication-dependent histone gene expression is a fundamental process occurring in S-phase under the control of the cyclin-E/CDK2 complex. This process is regulated by a number of proteins, including Flice-Associated Huge Protein (FLASH) (CASP8AP2), concentrated in specific nuclear organelles known as HLBs. FLASH regulates both histone gene transcription and mRNA maturation, and its downregulation in vitro results in the depletion of the histone pull and cell-cycle arrest in S-phase. Here we show that the transcription factor p73 binds to FLASH and is part of the complex that regulates histone gene transcription. Moreover, we created a novel gene trap to disrupt FLASH in mice, and we show that homozygous deletion of FLASH results in early embryonic lethality, owing to arrest of FLASH(-/-) embryos at the morula stage. These results indicate that FLASH is an essential, non-redundant regulator of histone transcription and cell cycle during embryogenesis.

Initial differences in lipid processing leading to pig-and beef-derived mature adipocyte differentiation

USDA-ARS?s Scientific Manuscript database

Clonal cultures of pig-derived mature adipocytes are capable of dedifferentiating and forming proliferative-competent progeny cells in vitro. Initial lipid processing, is different to that observed in cultures of beef-derived adipocytes. Mature pig adipocytes extrude lipid before proliferation, wher...

The allosteric HIV-1 integrase inhibitor BI-D affects virion maturation but does not influence packaging of a functional RNA genome.

PubMed

van Bel, Nikki; van der Velden, Yme; Bonnard, Damien; Le Rouzic, Erwann; Das, Atze T; Benarous, Richard; Berkhout, Ben

2014-01-01

The viral integrase (IN) is an essential protein for HIV-1 replication. IN inserts the viral dsDNA into the host chromosome, thereby aided by the cellular co-factor LEDGF/p75. Recently a new class of integrase inhibitors was described: allosteric IN inhibitors (ALLINIs). Although designed to interfere with the IN-LEDGF/p75 interaction to block HIV DNA integration during the early phase of HIV-1 replication, the major impact was surprisingly found on the process of virus maturation during the late phase, causing a reverse transcription defect upon infection of target cells. Virus particles produced in the presence of an ALLINI are misformed with the ribonucleoprotein located outside the virus core. Virus assembly and maturation are highly orchestrated and regulated processes in which several viral proteins and RNA molecules closely interact. It is therefore of interest to study whether ALLINIs have unpredicted pleiotropic effects on these RNA-related processes. We confirm that the ALLINI BI-D inhibits virus replication and that the produced virus is non-infectious. Furthermore, we show that the wild-type level of HIV-1 genomic RNA is packaged in virions and these genomes are in a dimeric state. The tRNAlys3 primer for reverse transcription was properly placed on this genomic RNA and could be extended ex vivo. In addition, the packaged reverse transcriptase enzyme was fully active when extracted from virions. As the RNA and enzyme components for reverse transcription are properly present in virions produced in the presence of BI-D, the inhibition of reverse transcription is likely to reflect the mislocalization of the components in the aberrant virus particle.

Assessing the impact of adjusting for maturity in weight status classification in a cross-sectional sample of UK children.

PubMed

Gillison, Fiona; Cumming, Sean; Standage, Martyn; Barnaby, Catherine; Katzmarzyk, Peter

2017-06-26

To compare the weight categorisation of a cohort of UK children using standard procedures (ie, comparing body mass index (BMI) centiles to age-matched UK reference data) versus an approach adjusted for maturation status (ie, matching relative to biological age). Analysis of data collected from an observational study of UK primary school children. Schools in South West England. Four hundred and seven 9-11 year-old children (98% white British). Weight status was classified using BMI centiles using (1) sex and chronological age-matched referents and (2) sex and biological age-matched referents (based on % of predicted adult stature) relative to UK 1990 reference growth charts. For both approaches, children were classified as a normal weight if >2nd centile and <85thcentile, overweight if 85th and <95thcentiles, and obese if ≥95thcentile. Fifty-one children (12.5%) were overweight, and a further 51 obese (12.5%) according to standard chronological age-matched classifications. Adjustment for maturity resulted in 32% of overweight girls, and 15% of overweight boys being reclassified as a normal weight, and 11% and 8% of obese girls and boys, respectively, being reclassified as overweight. Early maturing children were 4.9 times more likely to be reclassified from overweight to normal weight than 'on-time' maturers (OR 95% CI 1.3 to 19). Incorporating assessments of maturational status into weight classification resulted in significant changes to the classification of early-maturing adolescents. Further research exploring the implications for objective health risk and well-being is needed. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Multimethod Approach to the Early Postnatal Growth of the Mandible in Mice from a Zone of Robertsonian Polymorphism.

PubMed

Martínez-Vargas, Jessica; Muñoz-Muñoz, Francesc; López-Fuster, María José; Cubo, Jorge; Ventura, Jacint

2018-04-18

The western European house mouse (Mus musculus domesticus) shows high karyotypic diversity owing to Robertsonian translocations. Morphometric studies conducted with adult mice suggest that karyotype evolution due to these chromosomal reorganizations entails variation in the form and the patterns of morphological covariation of the mandible. However, information is much scarcer regarding the effect of these rearrangements on the growth pattern of the mouse mandible over early postnatal ontogeny. Here we compare mandible growth from the second to the eighth week of postnatal life between two ontogenetic series of mice from wild populations, with the standard karyotype and with Robertsonian translocations respectively, reared under the same conditions. A multi-method approach is used, including bone histology analyses of mandible surfaces and cross-sections, as well as geometric morphometric analyses of mandible form. The mandibles of both standard and Robertsonian mice display growth acceleration around weaning, anteroposterior direction of bone maturation, a predominance of bone deposition fields over ontogeny, and relatively greater expansion of the posterior mandible region correlated with the ontogenetic increase in mandible size. Nevertheless, differences exist between the two mouse groups regarding the timing of histological maturation of the mandible, the localization of certain bone remodeling fields, the temporospatial patterns of morphological variation, and the organization into two main modules. The dissimilarities in the process of mandible growth between the two groups of mice become more evident around sexual maturity, and could arise from alterations that Robertsonian translocations may exert on genes involved in the bone remodeling mechanism. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Regulation of germ cell development by intercellular signaling in the mammalian ovarian follicle.

PubMed

Clarke, Hugh J

2018-01-01

Prior to ovulation, the mammalian oocyte undergoes a process of differentiation within the ovarian follicle that confers on it the ability to give rise to an embryo. Differentiation comprises two phases-growth, during which the oocyte increases more than 100-fold in volume as it accumulates macromolecules and organelles that will sustain early embryogenesis; and meiotic maturation, during which the oocyte executes the first meiotic division and prepares for the second division. Entry of an oocyte into the growth phase appears to be triggered when the adjacent granulosa cells produce specific growth factors. As the oocyte grows, it elaborates a thick extracellular coat termed the zona pellucida. Nonetheless, cytoplasmic extensions of the adjacent granulosa cells, termed transzonal projections (TZPs), enable them to maintain contact-dependent communication with the oocyte. Through gap junctions located where the TZP tips meet the oocyte membrane, they provide the oocyte with products that sustain its metabolic activity and signals that regulate its differentiation. Conversely, the oocyte secretes diffusible growth factors that regulate proliferation and differentiation of the granulosa cells. Gap junction-permeable products of the granulosa cells prevent precocious initiation of meiotic maturation, and the gap junctions also enable oocyte maturation to begin in response to hormonal signals received by the granulosa cells. Development of the oocyte or the somatic compartment may also be regulated by extracellular vesicles newly identified in follicular fluid and at TZP tips, which could mediate intercellular transfer of macromolecules. Oocyte differentiation thus depends on continuous signaling interactions with the somatic cells of the follicle. WIREs Dev Biol 2018, 7:e294. doi: 10.1002/wdev.294 This article is categorized under: Gene Expression and Transcriptional Hierarchies > Cellular Differentiation Signaling Pathways > Cell Fate Signaling Early Embryonic Development > Gametogenesis. © 2017 Wiley Periodicals, Inc.

Temporal cohesion of the structural, functional and molecular characteristics of the developing zebrafish heart.

PubMed

Matrone, Gianfranco; Wilson, Kathryn S; Mullins, John J; Tucker, Carl S; Denvir, Martin A

2015-06-01

Heart formation is a complex, dynamic and highly coordinated process of molecular, morphogenetic and functional factors with each interacting and contributing to formation of the mature organ. Cardiac abnormalities in early life can be lethal in mammals but not in the zebrafish embryo which has been widely used to study the developing heart. While early cardiac development in the zebrafish has been well characterized, functional changes during development and how these relate to architectural, cellular and molecular aspects of development have not been well described previously. To address this we have carefully characterised cardiac structure, function, cardiomyocyte proliferation and cardiac-specific gene expression between 48 and 120 hpf in the zebrafish. We show that the zebrafish heart increases in volume and changes shape significantly between 48 and 72 hpf accompanied by a 40% increase in cardiomyocyte number. Between 96 and 120 hpf, while external heart expansion slows, there is rapid formation of a mature and extensive trabecular network within the ventricle chamber. While ejection fraction does not change during the course of development other determinants of contractile function increase significantly particularly between 72 and 96 hpf leading to an increase in cardinal vein blood flow. This study has revealed a number of novel aspects of cardiac developmental dynamics with striking temporal orchestration of structure and function within the first few days of development. These changes are associated with changes in expression of developmental and maturational genes. This study provides important insights into the complex temporal relationship between structure and function of the developing zebrafish heart. Copyright © 2015 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

Early executive function deficit in preterm children and its association with neurodevelopmental disorders in childhood: a literature review.

PubMed

Sun, Jing; Buys, Nicholas

2012-01-01

The purpose of this study is to examine the association of deficits of executive function (EF) and neurodevelopmental disorders in preterm children and the potential of assessing EF in infants as means of early identification. EF refers to a collection of related but somewhat discrete abilities, the main ones being working memory, inhibition, and planning. There is a general consensus that EF governs goal-directed behavior that requires holding those plans or programs on-line until executed, inhibiting irrelevant action and planning a sequence of actions. EF plays an essential role in cognitive development and is vital to individual social and intellectual success. Most researchers believe in the coordination and integrate cognitive-perceptual processes in relation to time and space, thus regulating higher-order cognitive processes, such as problem solving, reasoning, logical and flexible thinking, and decision-making. The importance of the maturation of the frontal lobe, particularly the prefrontal cortex, to the development of EF in childhood has been emphasized. Therefore, any abnormal development in the prefrontal lobes of infants and children could be expected to result in significant deficits in cognitive functioning. As this is a late-maturing part of the brain, various neurodevelopmental disorders, such as autism spectrum disorders, attention deficit hyperactivity disorder, language disorders, and schizophrenia, as well as acquired disorders of the right brain (and traumatic brain injury) impair EF, and the prefrontal cortex may be particularly susceptible to delayed development in these populations. The deficits of EF in infants are persistent into childhood and related to neurodevelopmental disorders in childhood and adolescence.

Topography of Slow Sigma Power during Sleep is Associated with Processing Speed in Preschool Children.

PubMed

Doucette, Margaret R; Kurth, Salome; Chevalier, Nicolas; Munakata, Yuko; LeBourgeois, Monique K

2015-11-04

Cognitive development is influenced by maturational changes in processing speed, a construct reflecting the rapidity of executing cognitive operations. Although cognitive ability and processing speed are linked to spindles and sigma power in the sleep electroencephalogram (EEG), little is known about such associations in early childhood, a time of major neuronal refinement. We calculated EEG power for slow (10-13 Hz) and fast (13.25-17 Hz) sigma power from all-night high-density electroencephalography (EEG) in a cross-sectional sample of healthy preschool children (n = 10, 4.3 ± 1.0 years). Processing speed was assessed as simple reaction time. On average, reaction time was 1409 ± 251 ms; slow sigma power was 4.0 ± 1.5 μV²; and fast sigma power was 0.9 ± 0.2 μV². Both slow and fast sigma power predominated over central areas. Only slow sigma power was correlated with processing speed in a large parietal electrode cluster (p < 0.05, r ranging from -0.6 to -0.8), such that greater power predicted faster reaction time. Our findings indicate regional correlates between sigma power and processing speed that are specific to early childhood and provide novel insights into the neurobiological features of the EEG that may underlie developing cognitive abilities.

Color back projection for fruit maturity evaluation

NASA Astrophysics Data System (ADS)

Zhang, Dong; Lee, Dah-Jye; Desai, Alok

2013-12-01

In general, fruits and vegetables such as tomatoes and dates are harvested before they fully ripen. After harvesting, they continue to ripen and their color changes. Color is a good indicator of fruit maturity. For example, tomatoes change color from dark green to light green and then pink, light red, and dark red. Assessing tomato maturity helps maximize its shelf life. Color is used to determine the length of time the tomatoes can be transported. Medjool dates change color from green to yellow, and the orange, light red and dark red. Assessing date maturity helps determine the length of drying process to help ripen the dates. Color evaluation is an important step in the processing and inventory control of fruits and vegetables that directly affects profitability. This paper presents an efficient color back projection and image processing technique that is designed specifically for real-time maturity evaluation of fruits. This color processing method requires very simple training procedure to obtain the frequencies of colors that appear in each maturity stage. This color statistics is used to back project colors to predefined color indexes. Fruit maturity is then evaluated by analyzing the reprojected color indexes. This method has been implemented and used for commercial production.

Accumulation of genistein and daidzein, soybean isoflavones implicated in promoting human health, is significantly elevated by irrigation.

PubMed

Bennett, John O; Yu, Oliver; Heatherly, Larry G; Krishnan, Hari B

2004-12-15

To circumvent drought conditions persisting during seed fill in the mid-south U.S. soybean production region, researchers have developed the early soybean (Glycine max [L.] Merr.) production system (ESPS), which entails early planting of short-season varieties. Because soybean supplies a preponderance of the world's protein and oil and consumption of soy-based foods has been associated with multiple health benefits, the effects of this agronomic practice on seed quality traits such as protein, oil, and isoflavones should be investigated. Four cultivars of soybean, two from maturity group IV and two from maturity group V, were planted in April (ESPS) and May (traditional) in a two-year study at Stoneville, MS. Near-infrared analysis of soybean seed was utilized to determine the percentages of protein and oil. Dependent upon variety, the oil content of the early-planted crop was increased by 3-8%, whereas protein was not significantly changed. Visualization of protein extracts fractionated by sodium dodecyl sulfate-polyacrylamide electrophoresis and fluorescence two-dimensional difference gel electrophoresis revealed that early planting did not affect the relative accumulation of the major seed-storage proteins; thus, protein composition was equal to that of traditionally cultivated soybeans. Maturity group IV cultivars contained a higher percentage of oil and a lower percentage of protein than did the maturity group V cultivars, regardless of planting date. Gas chromatographic separation of fatty acids revealed that the percentages of saturated and unsaturated fatty acids were not significantly altered by planting date. Methanol extracts of seed harvested from different planting dates when analyzed by high-performance liquid chromatography showed striking differences in isoflavone content. Dependent upon the variety, total isoflavone content was increased as much as 1.3-fold in early-planted soybeans. Irrigation enhanced the isoflavone content of both early- and late-planted soybeans as much as 2.5-fold. Accumulation of individual isoflavones, daidzein and genistein, was also elevated by irrigation. Because this cultural practice improves the quality traits of seeds, ESPS provides an opportunity for enhancing the quality of soybean.

Role of perinatal long-chain omega-3 fatty acids in cortical circuit maturation: Mechanisms and implications for psychopathology

PubMed Central

McNamara, Robert K; Vannest, Jennifer J; Valentine, Christina J

2015-01-01

Accumulating translational evidence suggests that the long-chain omega-3 fatty acid docosahexaenoic acid (DHA) plays a role in the maturation and stability of cortical circuits that are impaired in different recurrent psychiatric disorders. Specifically, rodent and cell culture studies find that DHA preferentially accumulates in synaptic and growth cone membranes and promotes neurite outgrowth, dendritic spine stability, and synaptogenesis. Additional evidence suggests that DHA may play a role in microglia-mediated synaptic pruning, as well as myelin development and resilience. In non-human primates n-3 fatty acid insufficiency during perinatal development leads to widespread deficits in functional connectivity in adult frontal cortical networks compared to primates raised on DHA-fortified diet. Preterm delivery in non-human primates and humans is associated with early deficits in cortical DHA accrual. Human preterm birth is associated with long-standing deficits in myelin integrity and cortical circuit connectivity and increased risk for attention deficit/hyperactivity disorder (ADHD), mood, and psychotic disorders. In general, ADHD and mood and psychotic disorders initially emerge during rapid periods of cortical circuit maturation and are characterized by DHA deficits, myelin pathology, and impaired cortical circuit connectivity. Together these associations suggest that early and uncorrected deficits in fetal brain DHA accrual may represent a modifiable risk factor for cortical circuit maturation deficits in psychiatric disorders, and could therefore have significant implications for informing early intervention and prevention strategies. PMID:25815252

Effects of feeding regimes and early maturation on migratory behaviour of landlocked hatchery-reared Atlantic salmon Salmo salar smolts.

PubMed

Norrgård, J R; Bergman, E; Schmitz, M; Greenberg, L A

2014-10-01

The migratory behaviour of hatchery-reared landlocked Atlantic salmon Salmo salar raised under three different feeding regimes was monitored through the lower part of the River Klarälven, Sweden. The smolts were implanted with acoustic transmitters and released into the River Klarälven, 25 km upstream of the outlet in Lake Vänern. Early mature males, which had matured the previous autumn, were also tagged and released. To monitor migration of the fish, acoustic receivers were deployed along the migratory route. The proportion of S. salar that reached Lake Vänern was significantly greater for fish fed fat-reduced feed than for fish given rations with higher fat content, regardless of ration size. Fish from the early mature male group remained in the river to a greater extent than fish from the three feeding regimes. Smolt status (degree of silvering), as visually assessed, did not differ among the feeding regime groups, and moreover, fully-silvered fish, regardless of feeding regime, migrated faster and had a greater migration success than fish with less developed smolt characteristics. Also, successful migrants had a lower condition factor than unsuccessful ones. These results indicate that the migration success of hatchery-reared S. smolts released to the wild can be enhanced by relatively simple changes in feeding regimes and by matching stocking time with smolt development. © 2014 The Fisheries Society of the British Isles.

STATISTICAL GROWTH MODELING OF LONGITUDINAL DT-MRI FOR REGIONAL CHARACTERIZATION OF EARLY BRAIN DEVELOPMENT.

PubMed

Sadeghi, Neda; Prastawa, Marcel; Fletcher, P Thomas; Gilmore, John H; Lin, Weili; Gerig, Guido

2012-01-01

A population growth model that represents the growth trajectories of individual subjects is critical to study and understand neurodevelopment. This paper presents a framework for jointly estimating and modeling individual and population growth trajectories, and determining significant regional differences in growth pattern characteristics applied to longitudinal neuroimaging data. We use non-linear mixed effect modeling where temporal change is modeled by the Gompertz function. The Gompertz function uses intuitive parameters related to delay, rate of change, and expected asymptotic value; all descriptive measures which can answer clinical questions related to growth. Our proposed framework combines nonlinear modeling of individual trajectories, population analysis, and testing for regional differences. We apply this framework to the study of early maturation in white matter regions as measured with diffusion tensor imaging (DTI). Regional differences between anatomical regions of interest that are known to mature differently are analyzed and quantified. Experiments with image data from a large ongoing clinical study show that our framework provides descriptive, quantitative information on growth trajectories that can be directly interpreted by clinicians. To our knowledge, this is the first longitudinal analysis of growth functions to explain the trajectory of early brain maturation as it is represented in DTI.

Puberty in subjects with complete androgen insensitivity syndrome.

PubMed

Papadimitriou, Dimitrios T; Linglart, Agnès; Morel, Yves; Chaussain, Jean-Louis

2006-01-01

Androgen receptor defects affect the regulation of the gonadotropic axis. However, little is known about the timing of pubertal maturation in complete androgen insensitivity syndrome (CAIS). To evaluate growth, skeletal maturation and gonadotropin and sex steroid secretion in patients with CAIS and intact gonads at puberty. Clinical, auxological and hormonal evaluation of 9 patients with CAIS from birth up to 17 years of age, prior to gonadectomy, in a single institution, retrospective study. Breast development occurred at a median age of 11.1 years, thumb sesamoid appeared at 11.5 years, and peak height velocity at 12.3 years, all consistent with average female values. However, median adult male height (+1.2 SDS) was closer to the patients' male target height (-0.3 SDS). Plasma testosterone levels rose early compared to normal boys. LH (basal and GnRH-stimulated) increased rapidly, above normal male values, in early puberty. This retrospective evaluation of a limited number of cases with a heterogeneous pattern of follow-up suggests that patients with CAIS may enter puberty at an age closer to female standards. These results imply a major role of direct androgen action, in utero or in early life, in determining the pattern of pubertal gonadotropin maturation.

Nezara viridula (Hemiptera: Pentatomidae) feeding patterns in macadamia nut in Hawaii: nut maturity and cultivar effects.

PubMed

Follett, Peter A; Wright, Mark G; Golden, Mary

2009-08-01

Nezara viridula L. (Hemiptera: Pentatomidae) is a serious pest of macadamia nuts, Macadamia integrifolia, in Hawaii. Using ruthenium red dye to stain stink bug feeding probes, feeding activity was determined for nuts of various maturity levels harvested from the tree and off the ground throughout the growing season in five commercial cultivars. Damage occurred in the tree and on the ground during all nut growth stages. Damage on the ground was often higher than in the tree. Cultivar 246 was more susceptible to attack than cultivars 333 and 800. It was previously thought that cultivar susceptibility was related to husk and shell thickness, but cultivar 246 showed higher damage than other cultivars even during early nut development when the nuts are small and before the shell has formed. This suggests that shell and husk thickness may play a secondary role in susceptibility to feeding by N. viridula. Monitoring N. viridula feeding activity during early nut development may help alert growers to potential problems later in the season, but early-season probing activity in immature nuts was not a good predictor of damage levels in mature nuts later in the season in our study.

Dietary starch breakdown product sensing mobilizes and apically activates α-glucosidases in small intestinal enterocytes.

PubMed

Chegeni, Mohammad; Amiri, Mahdi; Nichols, Buford L; Naim, Hassan Y; Hamaker, Bruce R

2018-02-20

Dietary starch is finally converted to glucose for absorption by the small intestine mucosal α-glucosidases (sucrase-isomaltase [SI] and maltase-glucoamylase), and control of this process has health implications. Here, the molecular mechanisms were analyzed associated with starch-triggered maturation and transport of SI. Biosynthetic pulse-chase in Caco-2 cells revealed that the high MW SI species (265 kDa) induced by maltose (an α-amylase starch digestion product) had a higher rate of early trafficking and maturation compared with a glucose-induced SI (245 kDa). The maltose-induced SI was found to have higher affinity to lipid rafts, which are associated with enhanced targeting to the apical membrane and higher activity. Accordingly, in situ maltose-hydrolyzing action was enhanced in the maltose-treated cells. Thus, starch digestion products at the luminal surface of small intestinal enterocytes are sensed and accelerate the intracellular processing of SI to enhance starch digestion capacity in the intestinal lumen.-Chegeni, M., Amiri, M., Nichols, B. L., Naim, H. Y., Hamaker, B. R. Dietary starch breakdown product sensing mobilizes and apically activates α-glucosidases in small intestinal enterocytes.

Origin and time-space distribution of hydrothermal systems in east-central Australian sedimentary basins: Constraints from illite geochronology and isotope geochemistry.

NASA Astrophysics Data System (ADS)

Uysal, I. Tonguç

2016-04-01

Some well-known precious mineral deposits and hydrocarbon resources occur extensively in east-central Australian sedimentary Basins. The metal occurrences are abundant in northwestern and eastern part of Queensland, whereas no significant deposits are known in large areas further south, which may, however, be hidden beneath the Jurassic-Cretaceous sedimentary basins. Important hydrocarbon resources exist within the Jurassic-Cretaceous sedimentary rocks at relatively shallow depths, of which the distribution represent zones of high paleo-geothermal gradients. This study examines the time-space distribution in relation to the regional tectonic history of concealed metal deposits and areas of high paleo-geothermal gradient leading to hydrocarbon maturation. To this end, authigenic illitic clay minerals representing various locations and stratigraphic depths in east-central Australia were investigated, of which the Rb-Sr and Ar-Ar geochronology and stable isotope geochemistry assist in delineating zones of hydrothermal systems responsible for hydro-carbon maturation/migration and potentially ore deposition. The Late Carboniferous - Early Permian crustal extension that affected large areas of eastern Australia and led to the epithermal mineralisations (e.g., the Drummond Basin) is also recorded in northern South Australia and southwest Queensland. A Late Triassic - Early Jurassic tectonic event being responsible for coal maturation and gas generation in the Bowen Basin and the epithermal mineralisation in the North Arm goldfield in SE Queensland likewise affected the areas much further west in Queensland. Some illites from the basement in outback Queensland and fault gouges from the Demon Fault in NE New South Wales yield younger Rb-Sr and Ar-Ar ages indicating the effect of hydrothermal processes as a result of a Middle-Upper Jurassic tectonic event. The majority of illite samples from the crystalline basement rocks, Permian Cooper Basin, and Jurassic-Cretaceous Eromanga Basin from all over east-central Australia give Cretaceous ages (~130 to ~60 Ma) reflecting episodic hydrothermal events restricted to certain tectonic zones. The Cretaceous events were responsible for the hydro-carbon generation/maturation in the Cooper, Eromanga, and Gunnedah Basins and deposition of some Au and basemetal resources in the eastern part of Queensland. The stable isotope composition of the Late Triassic - Early Jurassic illites in eastern Queensland and all mid-late Cretaceous illites from outback and eastern Australia is distinctively different with low 18O and D values indicating meteoric-hydrothermal systems due to extensional tectonics. Results of this study suggest that illite geochronology and geochemistry is a powerful tool in delineation of concealed hydrothermal systems that were responsible for ore generation and hydrocarbon/maturation and migration.

Early Cannabis Use, Polygenic Risk Score for Schizophrenia, and Brain Maturation in Adolescence

PubMed Central

French, Leon; Gray, Courtney; Leonard, Gabriel; Perron, Michel; Pike, G. Bruce; Richer, Louis; Séguin, Jean R.; Veillette, Suzanne; Evans, C. John; Artiges, Eric; Banaschewski, Tobias; Bokde, Arun W. L.; Bromberg, Uli; Bruehl, Ruediger; Buchel, Christian; Cattrell, Anna; Conrod, Patricia J.; Flor, Herta; Frouin, Vincent; Gallinat, Jurgen; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Lemaitre, Herve; Martinot, Jean-Luc; Nees, Frauke; Orfanos, Dimitri Papadopoulos; Pangelinan, Melissa Marie; Poustka, Luise; Rietschel, Marcella; Smolka, Michael N.; Walter, Henrik; Whelan, Robert; Timpson, Nic J.; Schumann, Gunter; Smith, George Davey; Pausova, Zdenka; Paus, Tomáš

2016-01-01

IMPORTANCE Cannabis use during adolescence is known to increase the risk for schizophrenia in men. Sex differences in the dynamics of brain maturation during adolescence may be of particular importance with regard to vulnerability of the male brain to cannabis exposure. OBJECTIVE To evaluate whether the association between cannabis use and cortical maturation in adolescents is moderated by a polygenic risk score for schizophrenia. DESIGN, SETTING, AND PARTICIPANTS Observation of 3 population-based samples included initial analysis in 1024 adolescents of both sexes from the Canadian Saguenay Youth Study (SYS) and follow-up in 426 adolescents of both sexes from the IMAGEN Study from 8 European cities and 504 male youth from the Avon Longitudinal Study of Parents and Children (ALSPAC) based in England. A total of 1577 participants (aged 12–21 years; 899 [57.0%] male) had (1) information about cannabis use; (2) imaging studies of the brain; and (3) a polygenic risk score for schizophrenia across 108 genetic loci identified by the Psychiatric Genomics Consortium. Data analysis was performed from March 1 through December 31, 2014. MAIN OUTCOMES AND MEASURES Cortical thickness derived from T1-weighted magnetic resonance images. Linear regression tests were used to assess the relationships between cannabis use, cortical thickness, and risk score. RESULTS Across the 3 samples of 1574 participants, a negative association was observed between cannabis use in early adolescence and cortical thickness in male participants with a high polygenic risk score. This observation was not the case for low-risk male participants or for the low- or high-risk female participants. Thus, in SYS male participants, cannabis use interacted with risk score vis-à-vis cortical thickness (P = .009); higher scores were associated with lower thickness only in males who used cannabis. Similarly, in the IMAGEN male participants, cannabis use interacted with increased risk score vis-à-vis a change in decreasing cortical thickness from 14.5 to 18.5 years of age (t137 = −2.36; P = .02). Finally, in the ALSPAC high-risk group of male participants, those who used cannabis most frequently (≥61 occasions) had lower cortical thickness than those who never used cannabis (difference in cortical thickness, 0.07 [95% CI, 0.01–0.12]; P = .02) and those with light use (<5 occasions) (difference in cortical thickness, 0.11 [95% CI, 0.03–0.18]; P = .004). CONCLUSIONS AND RELEVANCE Cannabis use in early adolescence moderates the association between the genetic risk for schizophrenia and cortical maturation among male individuals. This finding implicates processes underlying cortical maturation in mediating the link between cannabis use and liability to schizophrenia. PMID:26308966

Early Puberty in African-American Girls: Nutrition Past and Present.

ERIC Educational Resources Information Center

Talpade, Medha; Talpade, Salil

2001-01-01

Early sexual maturation is associated with many high-risk behaviors and a prediction was made that food consumption may contribute to early onset of puberty. A comparison was made between the eating habits of several generations of African-American women. Girls today were found to consume more calcium, grains, and meat then older women did in…

Do Trajectories of Household Risk in Childhood Moderate Pubertal Timing Effects on Substance Initiation in Middle School?

ERIC Educational Resources Information Center

Lynne-Landsman, Sarah D.; Graber, Julia A.; Andrews, Judy A.

2010-01-01

Previous research on pubertal timing has either evaluated contextual predictors of early puberty or negative adjustment outcomes associated with off-time development, especially early maturation. In this study, we integrated these 2 lines of research by evaluating the moderating influence of early childhood household risk on associations between…

A comparative study of ‘Fallglo’ and its seedless mutation ‘US Early Pride’ tangerines by sensory evaluation

USDA-ARS?s Scientific Manuscript database

‘Fallglo’ is an early-maturing tangerine hybrid commercially grown in Florida. It has high eating quality but contains many seeds, which is undesirable for consumers. ‘US Early Pride’, an irradiation-induced mutant of ‘Fallglo’, combines many quality attributes of ‘Fallglo’, but has very few seeds. ...

Evaluation of whole mount in situ hybridization as a tool for pathway-based toxicological research in early-life stage fathead minnows (poster)

EPA Science Inventory

Early-life stage fish can be more sensitive to chemical exposure than mature, adult fish. Therefore, defining adverse outcome pathways (AOPs) relevant to early-life stages is critical for linking perturbations of key events during fish development to potential adverse outcomes of...

Post-thymic maturation: young T cells assert their individuality.

PubMed

Fink, Pamela J; Hendricks, Deborah W

2011-07-22

T cell maturation was once thought to occur entirely within the thymus. Now, evidence is mounting that the youngest peripheral T cells in both mice and humans comprise a distinct population from their more mature, yet still naive, counterparts. These cells, termed recent thymic emigrants (RTEs), undergo a process of post-thymic maturation that can be monitored at the levels of cell phenotype and immune function. Understanding this final maturation step in the process of generating useful and safe T cells is of clinical relevance, given that RTEs are over-represented in neonates and in adults recovering from lymphopenia. Post-thymic maturation may function to ensure T cell fitness and self tolerance.

Visualisation of macropinosome maturation by the recruitment of sorting nexins.

PubMed

Kerr, Markus C; Lindsay, Margaret R; Luetterforst, Robert; Hamilton, Nicholas; Simpson, Fiona; Parton, Robert G; Gleeson, Paul A; Teasdale, Rohan D

2006-10-01

We report that phosphoinositol-binding sorting nexin 5 (SNX5) associates with newly formed macropinosomes induced by EGF stimulation. We used the recruitment of GFP-SNX5 to macropinosomes to track their maturation. Initially, GFP-SNX5 is sequestered to discrete subdomains of the macropinosome; these subdomains are subsequently incorporated into highly dynamic, often branched, tubular structures. Time-lapse videomicroscopy revealed the highly dynamic extension of SNX5-labelled tubules and their departure from the macropinosome body to follow predefined paths towards the perinuclear region of the cell, before fusing with early endosomal acceptor membranes. The extension and departure of these tubular structures occurs rapidly over 5-10 minutes and is dependent upon intact microtubules. As the tubular structures depart from the macropinosome there is a reduction in the surface area and an increase in tension of the limiting membrane of the macropinosome. In addition to the recruitment of SNX5 to the macropinosome, Rab5, SNX1 and EEA1 are also recruited by newly formed macropinosomes, followed by the accumulation of Rab7. SNX5 forms heterodimers with SNX1 and this interaction is required for endosome association of SNX5. We propose that the departure of SNX5-positive tubules represents a rapid mechanism of recycling components from macropinosomes thereby promoting their maturation into Rab7-positive structures. Collectively these findings provide a detailed real-time characterisation of the maturation process of the macropinocytic endosome.

Do physical maturity and birth date predict talent in male youth ice hockey players?

PubMed

Sherar, Lauren B; Baxter-Jones, Adam D G; Faulkner, Robert A; Russell, Keith W

2007-06-01

The aim of this study was to examine the relationships among biological maturity, physical size, relative age (i.e. birth date), and selection into a male Canadian provincial age-banded ice hockey team. In 2003, 619 male ice hockey players aged 14-15 years attended Saskatchewan provincial team selection camps, 281 of whom participated in the present study. Data from 93 age-matched controls were obtained from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-1997). During the initial selection camps, birth dates, heights, sitting heights, and body masses were recorded. Age at peak height velocity, an indicator of biological maturity, was determined in the controls and predicted in the ice hockey players. Data were analysed using one-way analysis of variance, logistic regression, and a Kolmogorov-Smirnov test. The ice hockey players selected for the final team were taller, heavier, and more mature (P < 0.05) than both the unselected players and the age-matched controls. Furthermore, age at peak height velocity predicted (P < 0.05) being selected at the first and second selection camps. The birth dates of those players selected for the team were positively skewed, with the majority of those selected being born in the months January to June. In conclusion, team selectors appear to preferentially select early maturing male ice hockey players who have birth dates early in the selection year.

Identification of Maturation-Specific Proteins by Single-Cell Proteomics of Human Oocytes

PubMed Central

Virant-Klun, Irma; Leicht, Stefan; Hughes, Christopher; Krijgsveld, Jeroen

2016-01-01

Oocytes undergo a range of complex processes via oogenesis, maturation, fertilization, and early embryonic development, eventually giving rise to a fully functioning organism. To understand proteome composition and diversity during maturation of human oocytes, here we have addressed crucial aspects of oocyte collection and proteome analysis, resulting in the first proteome and secretome maps of human oocytes. Starting from 100 oocytes collected via a novel serum-free hanging drop culture system, we identified 2,154 proteins, whose function indicate that oocytes are largely resting cells with a proteome that is tailored for homeostasis, cellular attachment, and interaction with its environment via secretory factors. In addition, we have identified 158 oocyte-enriched proteins (such as ECAT1, PIWIL3, NLRP7)1 not observed in high-coverage proteomics studies of other human cell lines or tissues. Exploiting SP3, a novel technology for proteomic sample preparation using magnetic beads, we scaled down proteome analysis to single cells. Despite the low protein content of only ∼100 ng per cell, we consistently identified ∼450 proteins from individual oocytes. When comparing individual oocytes at the germinal vesicle (GV) and metaphase II (MII) stage, we found that the Tudor and KH domain-containing protein (TDRKH) is preferentially expressed in immature oocytes, while Wee2, PCNA, and DNMT1 were enriched in mature cells, collectively indicating that maintenance of genome integrity is crucial during oocyte maturation. This study demonstrates that an innovative proteomics workflow facilitates analysis of single human oocytes to investigate human oocyte biology and preimplantation development. The approach presented here paves the way for quantitative proteomics in other quantity-limited tissues and cell types. Data associated with this study are available via ProteomeXchange with identifier PXD004142. PMID:27215607

Mettl3 Mutation Disrupts Gamete Maturation and Reduces Fertility in Zebrafish.

PubMed

Xia, Hui; Zhong, Chengrong; Wu, Xingxing; Chen, Ji; Tao, Binbin; Xia, Xiaoqin; Shi, Mijuan; Zhu, Zuoyan; Trudeau, Vance L; Hu, Wei

2018-02-01

N 6 -methyladenosine (m 6 A), catalyzed by Mettl3 methyltransferase, is a highly conserved epigenetic modification in eukaryotic messenger RNA (mRNA). Previous studies have implicated m 6 A modification in multiple biological processes, but the in vivo function of m 6 A has been difficult to study, because mettl3 mutants are embryonic lethal in both mammals and plants. In this study, we have used transcription activator-like effector nucleases and generated viable zygotic mettl3 mutant, Z mettl3 m/m , in zebrafish. We find that the oocytes in Z mettl3 m/m adult females are stalled in early development and the ratio of full-grown stage (FG) follicles is significantly lower than that of wild type. Human chorionic gonadotropin-induced ovarian germinal vesicle breakdown in vitro and the numbers of eggs ovulated in vivo are both decreased as well, while the defects of oocyte maturation can be rescued by sex hormone in vitro and in vivo In Z mettl3 m/m adult males, we find defects in sperm maturation and sperm motility is significantly reduced. Further study shows that 11-ketotestosterone (11-KT) and 17β-estradiol (E2) levels are significantly decreased in Z mettl3 m/m , and defective gamete maturation is accompanied by decreased overall m 6 A modification levels and disrupted expression of genes critical for sex hormone synthesis and gonadotropin signaling in Z mettl3 m/m Thus, our study provides the first in vivo evidence that loss of Mettl3 leads to failed gamete maturation and significantly reduced fertility in zebrafish. Mettl3 and m 6 A modifications are essential for optimal reproduction in vertebrates. Copyright © 2018 by the Genetics Society of America.

Identification of Maturation-Specific Proteins by Single-Cell Proteomics of Human Oocytes.

PubMed

Virant-Klun, Irma; Leicht, Stefan; Hughes, Christopher; Krijgsveld, Jeroen

2016-08-01

Oocytes undergo a range of complex processes via oogenesis, maturation, fertilization, and early embryonic development, eventually giving rise to a fully functioning organism. To understand proteome composition and diversity during maturation of human oocytes, here we have addressed crucial aspects of oocyte collection and proteome analysis, resulting in the first proteome and secretome maps of human oocytes. Starting from 100 oocytes collected via a novel serum-free hanging drop culture system, we identified 2,154 proteins, whose function indicate that oocytes are largely resting cells with a proteome that is tailored for homeostasis, cellular attachment, and interaction with its environment via secretory factors. In addition, we have identified 158 oocyte-enriched proteins (such as ECAT1, PIWIL3, NLRP7)(1) not observed in high-coverage proteomics studies of other human cell lines or tissues. Exploiting SP3, a novel technology for proteomic sample preparation using magnetic beads, we scaled down proteome analysis to single cells. Despite the low protein content of only ∼100 ng per cell, we consistently identified ∼450 proteins from individual oocytes. When comparing individual oocytes at the germinal vesicle (GV) and metaphase II (MII) stage, we found that the Tudor and KH domain-containing protein (TDRKH) is preferentially expressed in immature oocytes, while Wee2, PCNA, and DNMT1 were enriched in mature cells, collectively indicating that maintenance of genome integrity is crucial during oocyte maturation. This study demonstrates that an innovative proteomics workflow facilitates analysis of single human oocytes to investigate human oocyte biology and preimplantation development. The approach presented here paves the way for quantitative proteomics in other quantity-limited tissues and cell types. Data associated with this study are available via ProteomeXchange with identifier PXD004142. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

The effect of luteinizing hormone releasing hormone analog regime and stage of oocyte maturity for induced ovulation of channel catfish Ictalurus punctatus

USDA-ARS?s Scientific Manuscript database

The effective LHRHa (luteinizing hormone releasing hormone analog) dose based on the gonadal maturity of channel catfish, Ictalurus punctatus to optimize channel x blue hybrid catfish production was evaluated in 4 trials (twice in early part of the season and twice in the peak spawning season) in a ...

Validation of maturity offset in a longitudinal sample of Polish boys.

PubMed

Malina, Robert M; Kozieł, Sławomir M

2014-01-01

Abstract This study attempted to validate an anthropometric equation for predicting age at peak height velocity (APHV) in 193 Polish boys followed longitudinally 8-18 years (1961-1972). Actual APHV was derived with Preece-Baines Model 1. Predicted APHV was estimated at each observation using chronological age (CA), stature, mass, sitting height and estimated leg length. Mean predicted APHV increased from 8 to 18 years. Actual APHV was underestimated at younger ages and overestimated at older ages. Mean differences between predicted and actual APHV were reasonably stable between 13 and 15 years. Predicted APHV underestimated actual APHV 3 years before, was almost identical with actual age 2 years before, and then overestimated actual age through 3 years after PHV. Predicted APHV did not differ among boys of contrasting maturity status 8-11 years, but diverged among groups 12-15 years. In conclusion, predicted APHV is influenced by CA and by early and late timing of actual PHV. Predicted APHV has applicability among average maturing boys 12-16 years in contrast to late and early maturing boys. Dependence upon age and individual differences in actual APHV limits utility of predicted APHV in research with male youth athletes and in talent programmes.

Morphological and proteomic analysis of early stage of osteoblast differentiation in osteoblastic progenitor cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Dun; Orthopedic Department, Taizhou Hospital, Wenzhou Medical College, Linhai, Zhejiang 317000; Chen, Hai-Xiao, E-mail: Hxchen-1@163.net

Bone remodeling relies on a dynamic balance between bone formation and resorption, mediated by osteoblasts and osteoclasts, respectively. Under certain stimuli, osteoprogenitor cells may differentiate into premature osteoblasts and further into mature osteoblasts. This process is marked by increased alkaline phosphatase (ALP) activity and mineralized nodule formation. In this study, we induced osteoblast differentiation in mouse osteoprogenitor MC3T3-E1 cells and divided the process into three stages. In the first stage (day 3), the MC3T3-E1 cell under osteoblast differentiation did not express ALP or deposit a mineralized nodule. In the second stage, the MC3T3-E1 cell expressed ALP but did not formmore » a mineralized nodule. In the third stage, the MC3T3-E1 cell had ALP activity and formed mineralized nodules. In the present study, we focused on morphological and proteomic changes of MC3T3-E1 cells in the early stage of osteoblast differentiation - a period when premature osteoblasts transform into mature osteoblasts. We found that mean cell area and mean stress fiber density were increased in this stage due to enhanced cell spreading and decreased cell proliferation. We further analyzed the proteins in the signaling pathway of regulation of the cytoskeleton using a proteomic approach and found upregulation of IQGAP1, gelsolin, moesin, radixin, and Cfl1. After analyzing the focal adhesion signaling pathway, we found the upregulation of FLNA, LAMA1, LAMA5, COL1A1, COL3A1, COL4A6, and COL5A2 as well as the downregulation of COL4A1, COL4A2, and COL4A4. In conclusion, the signaling pathway of regulation of the cytoskeleton and focal adhesion play critical roles in regulating cell spreading and actin skeleton formation in the early stage of osteoblast differentiation.« less

Effect of sericin supplementation in maturation medium on cumulus cell expansion, oocyte nuclear maturation, and subsequent embryo development in Sanjabi ewes during the breeding season.

PubMed

Aghaz, F; Hajarian, H; Shabankareh, H Karami; Abdolmohammadi, A

2015-12-01

The purpose of this study was to evaluate the effect of sericin with different concentrations (0% [control], 0.1%, 0.5%, 1.0%, and 2.5%) added to the IVM medium on cumulus cell expansion, oocyte nuclear maturation, and subsequent embryo development in Sanjabi ewes during the breeding season. The resumption of meiosis was assessed by the frequency of germinal vesicle breakdown and the first polar body extrusion. After IVF with fresh ram semen, presumptive zygotes were cultured 8 days in potassium simplex optimization medium supplemented by amino acids, and the percentages developing to the two-cell and blastocyst stages were measured as the indicators of early embryonic developmental competence. More cumulus-oocyte complexes matured with 0.5% sericin underwent germinal vesicle breakdown and reached metaphase II stage compared with the control cumulus-oocyte complexes matured without sericin (P ≤ 0.05). The present findings indicated that supplementation with 0.5% sericin during the maturation culture may improve the nuclear maturation and the cumulus cell expansion. Furthermore, the percentage of blastocysts obtained from 0.5% and 0.1% sericin (37.8 ± 1.76% and 34.8 ± 1.09%, respectively) was higher (P ≤ 0.05) than that of the control medium (29.60 ± 1.67%). However, addition of 1% and 2.5% of sericin to the IVM medium oocytes had a negative effect on nuclear maturation and cumulus cell expansion. Furthermore, the percentage of cleavage and blastocyst rate was significantly lower in the 1% and 2.5% sericin groups than in the control group. These findings showed that supplementation of IVM medium with 0.5% sericin may improve the meiotic competence of oocytes and early embryonic development in Sanjabi ewes during the breeding season. Copyright © 2015 Elsevier Inc. All rights reserved.

Microscopic dynamics research on the "mature" process of dye-sensitized solar cells after injection of highly concentrated electrolyte.

PubMed

Liang, Zhongguan; Liu, Weiqing; Chen, Jun; Hu, Linhua; Dai, Songyuan

2015-01-21

After injection of electrolyte, the internal three-dimensional solid-liquid penetration system of dye-sensitized solar cells (DSCs) can take a period of time to reach "mature" state. This paper studies the changes of microscopic processes of DSCs including TiO2 energy-level movement, localized state distribution, charge accumulation, electron transport, and recombination dynamics, from the beginning of electrolyte injection to the time of reached mature state. The results show that the microscopic dynamics process of DSCs exhibited a time-dependent behavior and achieved maturity ∼12 h after injecting the electrolyte into DSCs. Within 0-12 h, several results were observed: (1) the conduction band edge of TiO2 moved slightly toward negative potential direction; (2) the localized states in the band gap of TiO2 was reduced according to the same distribution law; (3) the transport resistance in TiO2 film increased, and electron transport time was prolonged as the time of maturity went on, which indicated that the electron transport process is impeded gradually; (4) the recombination resistance at the TiO2/electrolyte (EL) interface increases, and electron lifetime gradually extends, therefore, the recombination process is continuously suppressed. Furthermore, results suggest that the parameters of EL/Pt-transparent conductive oxide (TCO) interface including the interfacial capacitance, electron-transfer resistance, and transfer time constant would change with time of maturity, indicating that the EL/Pt-TCO interface is a potential factor affecting the mature process of DSCs.

Efficacy of abbreviated Stanford V chemotherapy and involved-field radiotherapy in early-stage Hodgkin lymphoma: mature results of the G4 trial.

PubMed

Advani, R H; Hoppe, R T; Baer, D; Mason, J; Warnke, R; Allen, J; Daadi, S; Rosenberg, S A; Horning, S J

2013-04-01

To assess the efficacy of an abbreviated Stanford V regimen in patients with early-stage Hodgkin lymphoma (HL). PATIENTS AND METHODS PATIENTS: with untreated nonbulky stage I-IIA supradiaphragmatic HL were eligible for the G4 study. Stanford V chemotherapy was administered for 8 weeks followed by radiation therapy (RT) 30 Gy to involved fields (IF). Freedom from progression (FFP), disease-specific survival (DSS) and overall survival (OS) were estimated. All 87 enrolled patients completed the abbreviated regimen. At a median follow-up of 10 years, FFP, DSS and OS are 94%, 99% and 94%, respectively. Therapy was well tolerated with no treatment-related deaths. Mature results of the abbreviated Stanford V regimen in nonbulky early-stage HL are excellent and comparable to the results from other contemporary therapies.

Gonad development during the early life of Octopus maya (Mollusca: Cephalopoda).

PubMed

Avila-Poveda, Omar Hernando; Colin-Flores, Rafael Francisco; Rosas, Carlos

2009-02-01

Gonad development during the early life of Octopus maya is described in terms of histological, morphometric, oocytes growth, and somatic-oocyte relationship data obtained from octopus cultured at the UMDI-UNAM, in Sisal, Yucatan, Mexico. This study is the first publication on gonad development during the early life of Octopus maya. A total of 83 O. maya specimens were used; their sizes ranged from 6.5 to 76 mm of total length (TL), 4 to 28 mm of dorsal mantle length (DML), 2.5 to 20 mm of ventral mantle length (VML), and 0.0180 to 7.2940 g of fixed body weight (fBW). Animals were weighed and measured only after preservation. A loss of 10% of living weight was estimated for juvenile octopuses after formalin preservation. The relation of length to weight (VML, DML, TL/fBW) pooled for both sexes had a strong positive correlation (r), as shown by a potential power function that was quite close to 1. Compound images were produced from numerous microscopic fields. The histological examination revealed that, 4 months after hatching, male octopus (24.5 mm DML and 7.2940 g fBW) were in gonad stages 2 (maturing) to 3 (mature), with spermatogonia and spermatocytes in the tubule wall and abundant spermatids and spermatozoa in the central lumen of the seminiferous tubules, suggesting the occurrence of different phases of gonad development at different maturity stages. In contrast, females (22.5 mm DML and 4.8210 g fBW) at the same time since hatching were immature (stage 1), with many oogonia, few oocytes, and germinal epithelium. This suggests that males reach maturity earlier than females, indicating a probable onset of maturity for males at around 4 months of culture or 8 g of wet body weight. Our results indicate the possibility that the size-at-weight can be recognized early with a degree of certainty that allows the sexes to be separated for culture purposes; but more detailed studies on reproduction in relation to endocrinology and nutrition are needed.

Pet-1 Switches Transcriptional Targets Postnatally to Regulate Maturation of Serotonin Neuron Excitability.

PubMed

Wyler, Steven C; Spencer, W Clay; Green, Noah H; Rood, Benjamin D; Crawford, LaTasha; Craige, Caryne; Gresch, Paul; McMahon, Douglas G; Beck, Sheryl G; Deneris, Evan

2016-02-03

Newborn neurons enter an extended maturation stage, during which they acquire excitability characteristics crucial for development of presynaptic and postsynaptic connectivity. In contrast to earlier specification programs, little is known about the regulatory mechanisms that control neuronal maturation. The Pet-1 ETS (E26 transformation-specific) factor is continuously expressed in serotonin (5-HT) neurons and initially acts in postmitotic precursors to control acquisition of 5-HT transmitter identity. Using a combination of RNA sequencing, electrophysiology, and conditional targeting approaches, we determined gene expression patterns in maturing flow-sorted 5-HT neurons and the temporal requirements for Pet-1 in shaping these patterns for functional maturation of mouse 5-HT neurons. We report a profound disruption of postmitotic expression trajectories in Pet-1(-/-) neurons, which prevented postnatal maturation of 5-HT neuron passive and active intrinsic membrane properties, G-protein signaling, and synaptic responses to glutamatergic, lysophosphatidic, and adrenergic agonists. Unexpectedly, conditional targeting revealed a postnatal stage-specific switch in Pet-1 targets from 5-HT synthesis genes to transmitter receptor genes required for afferent modulation of 5-HT neuron excitability. Five-HT1a autoreceptor expression depended transiently on Pet-1, thus revealing an early postnatal sensitive period for control of 5-HT excitability genes. Chromatin immunoprecipitation followed by sequencing revealed that Pet-1 regulates 5-HT neuron maturation through direct gene activation and repression. Moreover, Pet-1 directly regulates the 5-HT neuron maturation factor Engrailed 1, which suggests Pet-1 orchestrates maturation through secondary postmitotic regulatory factors. The early postnatal switch in Pet-1 targets uncovers a distinct neonatal stage-specific function for Pet-1, during which it promotes maturation of 5-HT neuron excitability. The regulatory mechanisms that control functional maturation of neurons are poorly understood. We show that in addition to inducing brain serotonin (5-HT) synthesis and reuptake, the Pet-1 ETS (E26 transformation-specific) factor subsequently globally coordinates postmitotic expression trajectories of genes necessary for maturation of 5-HT neuron excitability. Further, Pet-1 switches its transcriptional targets as 5-HT neurons mature from 5-HT synthesis genes to G-protein-coupled receptors, which are necessary for afferent synaptic modulation of 5-HT neuron excitability. Our findings uncover gene-specific switching of downstream targets as a previously unrecognized regulatory strategy through which continuously expressed transcription factors control acquisition of neuronal identity at different stages of development. Copyright © 2016 the authors 0270-6474/16/361758-17$15.00/0.

Detection and Characterization of Aggregates, Prefibrillar Amyloidogenic Oligomers, and Protofibrils Using Fluorescence Spectroscopy

PubMed Central

Lindgren, Mikael; Sörgjerd, Karin; Hammarström, Per

2005-01-01

Transthyretin (TTR) is a protein linked to a number of different amyloid diseases including senile systemic amyloidosis and familial amyloidotic polyneuropathy. The transient nature of oligomeric intermediates of misfolded TTR that later mature into fibrillar aggregates makes them hard to study, and methods to study these species are sparse. In this work we explore a novel pathway for generation of prefibrillar aggregates of TTR, which provides important insight into TTR misfolding. Prefibrillar amyloidogenic oligomers and protofibrils of misfolded TTR were generated in vitro through induction of the molten globule type A-state from acid unfolded TTR through the addition of NaCl. The aggregation process produced fairly monodisperse oligomers (300–500 kD) within 2 h that matured after 20 h into larger spherical clusters (30–50 nm in diameter) and protofibrils as shown by transmission electron microscopy. Further maturation of the aggregates showed shrinkage of the spheres as the fibrils grew in length, suggesting a conformational change of the spheres into more rigid structures. The structural and physicochemical characteristics of the aggregates were investigated using fluorescence, circular dichroism, chemical cross-linking, and transmission electron microscopy. The fluorescent dyes 1-anilinonaphthalene-8-sulfonate (ANS), 4-4-bis-1-phenylamino-8-naphthalene sulfonate (Bis-ANS), 4-(dicyanovinyl)-julolidine (DCVJ), and thioflavin T (ThT) were employed in both static and kinetic assays to characterize these oligomeric and protofibrillar states using both steady-state and time-resolved fluorescence techniques. DCVJ, a molecular rotor, was employed for the first time for studies of an amyloidogenic process and is shown useful for detection of the early steps of the oligomerization process. DCVJ bound to the early prefibrillar oligomers (300–500 kD) with an apparent dissociation constant of 1.6 μM, which was slightly better than for ThT (6.8 μM). Time-resolved fluorescence anisotropy decay of ANS was shown to be a useful tool for giving further structural and kinetic information of the oligomeric aggregates. ThT dramatically increases its fluorescence quantum yield when bound to amyloid fibrils; however, the mechanism behind this property is unknown. Data from this work suggest that unbound ThT is also intrinsically quenched and functions similarly to a molecular rotor, which in combination with its environmental dependence provides a blue shift to the characteristic 482 nm wavelength when bound to amyloid fibrils. PMID:15764666

Intracellular Distribution of Capsid-Associated pUL77 of Human Cytomegalovirus and Interactions with Packaging Proteins and pUL93.

PubMed

Köppen-Rung, Pánja; Dittmer, Alexandra; Bogner, Elke

2016-07-01

DNA packaging into procapsids is a common multistep process during viral maturation in herpesviruses. In human cytomegalovirus (HCMV), the proteins involved in this process are terminase subunits pUL56 and pUL89, which are responsible for site-specific cleavage and insertion of the DNA into the procapsid via portal protein pUL104. However, additional viral proteins are required for the DNA packaging process. We have shown previously that the plasmid that encodes capsid-associated pUL77 encodes another potential player during capsid maturation. Pulse-chase experiments revealed that pUL77 is stably expressed during HCMV infection. Time course analysis demonstrated that pUL77 is expressed in the early late part of the infectious cycle. The sequence of pUL77 was analyzed to find nuclear localization sequences (NLSs), revealing monopartite NLSm at the N terminus and bipartite NLSb in the middle of pUL77. The potential NLSs were inserted into plasmid pHM829, which encodes a chimeric protein with β-galactosidase and green fluorescent protein. In contrast to pUL56, neither NLSm nor NLSb was sufficient for nuclear import. Furthermore, we investigated by coimmunoprecipitation whether packaging proteins, as well as pUL93, the homologue protein of herpes simplex virus 1 pUL17, are interaction partners of pUL77. The interactions between pUL77 and packaging proteins, as well as pUL93, were verified. We showed that the capsid-associated pUL77 is another potential player during capsid maturation of HCMV. Protein UL77 (pUL77) is a conserved core protein of HCMV. This study demonstrates for the first time that pUL77 has early-late expression kinetics during the infectious cycle and an intrinsic potential for nuclear translocation. According to its proposed functions in stabilization of the capsid and anchoring of the encapsidated DNA during packaging, interaction with further DNA packaging proteins is required. We identified physical interactions with terminase subunits pUL56 and pUL89 and another postulated packaging protein, pUL93, in infected, as well as transfected, cells. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Artificial maturation of an immature sulfur- and organic matter-rich limestone from the Ghareb Formation, Jordan

USGS Publications Warehouse

Koopmans, M.P.; Rijpstra, W.I.C.; De Leeuw, J. W.; Lewan, M.D.; Damste, J.S.S.

1998-01-01

An immature (Ro=0.39%), S-rich (S(org)/C = 0.07), organic matter-rich (19.6 wt. % TOC) limestone from the Ghareb Formation (Upper Cretaceous) in Jordan was artificially matured by hydrous pyrolysis (200, 220 ..., 300??C; 72 h) to study the effect of progressive diagenesis and early catagenesis on the amounts and distributions of hydrocarbons, organic sulfur compounds and S-rich geomacromolecules. The use of internal standards allowed the determination of absolute amounts. With increasing thermal maturation, large amounts of alkanes and alkylthiophenes with predominantly linear carbon skeletons are generated from the kerogen. The alkylthiophene isomer distributions do not change significantly with increasing thermal maturation, indicating the applicability of alkylthiophenes as biomarkers at relatively high levels of thermal maturity. For a given carbon skeleton, the saturated hydrocarbon, alkylthiophenes and alkylbenzo[b]thiophenes are stable forms at relatively high temperatures, whereas the alkylsulfides are not stable. The large amount of alkylthiophenes produced relative to the alkanes may be explained by the large number of monosulfide links per carbon skeleton. These results are in good agreement with those obtained previously for an artificial maturation series of an immature S-rich sample from the Gessoso-solfifera Formation.An immature (Ro = 0.39%), S-rich (Sorg/C = 0.07), organic matter-rich (19.6 wt.% TOC) limestone from the Ghareb Formation (Upper Cretaceous) in Jordan was artificially matured by hydrous pyrolysis (200, 220, ..., 300??C; 72 h) to study the effect of progressive diagenesis and early catagenesis on the amounts and distributions of hydrocarbons, organic sulfur compounds and S-rich geomacromolecules. The use of internal standards allowed the determination of absolute amounts. With increasing thermal maturation, large amounts of alkanes and alkylthiophenes with predominantly linear carbon skeletons are generated from the kerogen. The alkylthiophene isomer distributions do not change significantly with increasing thermal maturation, indicating the applicability of alkylthiophenes as biomarkers at relatively high levels of thermal maturity. For a given carbon skeleton, the saturated hydrocarbon, alkylthiophene and alkylbenzo[b]thiophenes are stable forms at relatively high temperatures, whereas the alkylsulfides are not stable. The large amount of alkylthiophenes produced relative to the alkanes may be explained by the large number of monosulfide links per carbon skeleton. These results are in good agreement with those obtained previously for an artificial maturation series of an immature S-rich sample from the Gessoso-solfifera Formation.

Development of visual cortical function in infant macaques: A BOLD fMRI study

PubMed Central

Meeson, Alan; Munk, Matthias H. J.; Kourtzi, Zoe; Movshon, J. Anthony; Logothetis, Nikos K.; Kiorpes, Lynne

2017-01-01

Functional brain development is not well understood. In the visual system, neurophysiological studies in nonhuman primates show quite mature neuronal properties near birth although visual function is itself quite immature and continues to develop over many months or years after birth. Our goal was to assess the relative development of two main visual processing streams, dorsal and ventral, using BOLD fMRI in an attempt to understand the global mechanisms that support the maturation of visual behavior. Seven infant macaque monkeys (Macaca mulatta) were repeatedly scanned, while anesthetized, over an age range of 102 to 1431 days. Large rotating checkerboard stimuli induced BOLD activation in visual cortices at early ages. Additionally we used static and dynamic Glass pattern stimuli to probe BOLD responses in primary visual cortex and two extrastriate areas: V4 and MT-V5. The resulting activations were analyzed with standard GLM and multivoxel pattern analysis (MVPA) approaches. We analyzed three contrasts: Glass pattern present/absent, static/dynamic Glass pattern presentation, and structured/random Glass pattern form. For both GLM and MVPA approaches, robust coherent BOLD activation appeared relatively late in comparison to the maturation of known neuronal properties and the development of behavioral sensitivity to Glass patterns. Robust differential activity to Glass pattern present/absent and dynamic/static stimulus presentation appeared first in V1, followed by V4 and MT-V5 at older ages; there was no reliable distinction between the two extrastriate areas. A similar pattern of results was obtained with the two analysis methods, although MVPA analysis showed reliable differential responses emerging at later ages than GLM. Although BOLD responses to large visual stimuli are detectable, our results with more refined stimuli indicate that global BOLD activity changes as behavioral performance matures. This reflects an hierarchical development of the visual pathways. Since fMRI BOLD reflects neural activity on a population level, our results indicate that, although individual neurons might be adult-like, a longer maturation process takes place on a population level. PMID:29145469

Small G Rac1 is involved in replication cycle of dengue serotype 2 virus in EAhy926 cells via the regulation of actin cytoskeleton.

PubMed

Zhang, Jing; Wu, Na; Gao, Na; Yan, Wenli; Sheng, Ziyang; Fan, Dongying; An, Jing

2016-05-01

Bleeding is a clinical characteristic of severe dengue and may be due to increased vascular permeability. However, the pathogenesis of severe dengue remains unclear. In this study, we showed that the Rac1-microfilament signal pathway was involved in the process of DENV serotype 2 (DENV2) infection in EAhy926 cells. DENV2 infection induced dynamic changes in actin organization, and treatment with Cytochalasin D or Jasplakinolide disrupted microfilament dynamics, reduced DENV2 entry, and inhibited DENV2 assembly and maturation. Rac1 activities decreased during the early phase and gradually increased by the late phase of infection. Expression of the dominant-negative form of Rac1 promoted DENV2 entry but inhibited viral assembly, maturation and release. Our findings demonstrated that Rac1 plays an important role in the DENV2 life cycle by regulating actin reorganization in EAhy926 cells. This finding provides further insight into the pathogenesis of severe dengue.

Peer Influences on Adolescent Decision Making.

PubMed

Albert, Dustin; Chein, Jason; Steinberg, Laurence

2013-04-01

Research efforts to account for elevated risk behavior among adolescents have arrived at an exciting new stage. Moving beyond laboratory studies of age differences in "cool" cognitive processes related to risk perception and reasoning, new approaches have shifted focus to the influence of social and emotional factors on adolescent neurocognition. We review recent research suggesting that adolescent risk-taking propensity derives in part from a maturational gap between early adolescent remodeling of the brain's socio-emotional reward system and a gradual, prolonged strengthening of the cognitive control system. At a time when adolescents spend an increasing amount of time with their peers, research suggests that peer-related stimuli may sensitize the reward system to respond to the reward value of risky behavior. As the cognitive control system gradually matures over the course of the teenage years, adolescents grow in their capacity to coordinate affect and cognition, and to exercise self-regulation even in emotionally arousing situations. These capacities are reflected in gradual growth in the capacity to resist peer influence.

Plasma cell output from germinal centers is regulated by signals from Tfh and stromal cells

PubMed Central

George, Laura A.; Acs, Andreas; Durrett, Russell E.

2018-01-01

Germinal centers (GCs) are the sites where B cells undergo affinity maturation. The regulation of cellular output from the GC is not well understood. Here, we show that from the earliest stages of the GC response, plasmablasts emerge at the GC–T zone interface (GTI). We define two main factors that regulate this process: Tfh-derived IL-21, which supports production of plasmablasts from the GC, and TNFSF13 (APRIL), which is produced by a population of podoplanin+ CD157high fibroblastic reticular cells located in the GTI that are also rich in message for IL-6 and chemokines CXCL12, CCL19, and CCL21. Plasmablasts in the GTI express the APRIL receptor TNFRSF13B (TACI), and blocking TACI interactions specifically reduces the numbers of plasmablasts appearing in the GTI. Plasma cells generated in the GTI may provide an early source of affinity-matured antibodies that may neutralize pathogens or provide feedback regulating GC B cell selection. PMID:29549115

Bone age in children with obstetrical brachial plexus palsy: effect of peripheral nerve injury on skeletal maturation.

PubMed

Oktay, Fügen; Cömert, Didem; Gökkaya, Nilüfer Kutay Ordu; Ozbudak, Sibel Demir; Uysal, Hilmi

2014-02-01

The purpose of this retrospective study was to analyze the effect of peripheral nerve injury on the skeletal maturation process. The bone ages of the affected and unaffected hand-wrists of 42 children with obstetrical brachial palsy were determined according to the Greulich and Pyle atlas. In 23 patients, the bone ages of the both sides were identical (bone-age-symmetrical group), in 19 patients the bone age of the affected side was delayed (bone-age-delayed group). The mean bone age of the affected side was delayed 0.48 ± 0.25 years that of the unaffected side (P = .000), and the delay of bone age was inversely correlated with chronological age (R (2) = .45, P < .02) in the bone-age-delayed group. Skeletal retardation can be recognized after appearance of ossification centers by plain radiography, dating from the third month of life, in early infancy. Thus, bone age determination method might be helpful for predicting potential future limb shortness.

Exploring microbial succession and diversity during solid-state fermentation of Tianjin duliu mature vinegar.

PubMed

Nie, Zhiqiang; Zheng, Yu; Wang, Min; Han, Yue; Wang, Yuenan; Luo, Jianmei; Niu, Dandan

2013-11-01

Tianjin duliu mature vinegar was one of famous Chinese traditional vinegars. The unique flavor and taste of vinegar are mainly generated by the multitudinous microorganisms during fermentation. In this research, the composition and succession of microbial communities in the entire solid-state fermentation were investigated, including starter daqu and acetic acid fermentation (AAF). Molds and yeasts in daqu, including Aspergillus, Saccharomycopsis and Pichia, decreased in AAF. The bacterial compositions increased from four genera in daqu to more than 13 genera in AAF. Principal component analysis showed that Acetobacter, Gluconacetobacter, Lactobacillus and Nostoc were dominant bacteria that were correlated well with AAF process. In the early fermentation period, lactic acid bacteria (LAB) decreased while acetic acid bacteria and Nostoc increased rapidly with the accumulation of total acids. Then, the abundance and diversity of LAB increased (more than 80%), indicating that LAB had important influences on the flavor and taste of vinegar. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of delignification upon in vitro digestion of forage cellulose.

PubMed

Darcy, B K; Belyea, R L

1980-10-01

Orchardgrass forages harvested at two maturities (early and late) were ground through two screens (1 and 8 mm) and digested in vitro as intact forage and forage delignified by permanganate oxidation. Initial and residual cell wall, initial and residual cellulose and potentially digestible cellulose were greater in late intact forage than in the early. In the delignified forage, late cut forage had less residual cellulose than did the early, but initial and potentially digestible cellulose were similar. Particle size had less consistent and smaller effects upon cell wall and cellulose than did maturity. Cellulose of intact orchardgrass was 64% digested at 72 h vs 94% for cellulose of delignified orchardgrass. Digestion rate of cellulose was .0197 and .0220 logn units/hr for early and late cut intact forage and .0554 and .0719 logn units/hr for early and late cut delignified forage. Removal of the inhibitory effects of lignin increased the amount of digestible cellulose, increased the rate at which cellulose degraded and decreased the indigestible cellulose residue. Reduction in lignin could greatly improve forage intake and utilization at moderate levels of animal production.

Evolution of microbial dynamics during the maturation phase of the composting of different types of waste.

PubMed

Villar, Iria; Alves, David; Garrido, Josefina; Mato, Salustiano

2016-08-01

During composting, facilities usually exert greater control over the bio-oxidative phase of the process, which uses a specific technology and generally has a fixed duration. After this phase, the material is deposited to mature, with less monitoring during the maturation phase. While there has been considerable study of biological parameters during the thermophilic phase, there is less research on the stabilization and maturation phase. This study evaluates the effects of the type of starting material on the evolution of microbial dynamics during the maturation phase of composting. Three waste types were used: sludge from the fish processing industry, municipal sewage sludge and pig manure, each independently mixed with shredded pine wood as bulking agent. The composting system for each waste type comprised a static reactor with capacity of 600L for the bio-oxidative phase followed by stabilization and maturation phase in triplicate 200L boxes for 112days. Phospholipid fatty acids, enzyme activities and physico-chemical parameters were measured throughout the maturation phase. The evolution of the total microbial biomass, Gram + bacteria, Gram - bacteria, fungi and enzymatic activities (β-glucosidase, cellulase, protease, acid and alkaline phosphatase) depended significantly on the waste type (p<0.001). The predominant microbial community for each waste type remained present throughout the maturation process, indicating that the waste type determines the microorganisms that are able to develop at this stage. While fungi predominated during fish sludge maturation, manure and municipal sludge were characterized by a greater proportion of bacteria. Both the structure of the microbial community and enzymatic activities provided important information for monitoring the composting process. More attention should be paid to the maturation phase in order to optimize composting. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Ontogeny of vestibular compound action potentials in the domestic chicken

NASA Technical Reports Server (NTRS)

Jones, S. M.; Jones, T. A.

2000-01-01

Compound action potentials of the vestibular nerve were measured from the surface of the scalp in 148 chickens (Gallus domesticus). Ages ranged from incubation day 18 (E18) to 22 days posthatch (P22). Responses were elicited using linear acceleration cranial pulses. Response thresholds decreased at an average rate of -0.45 dB/day. The decrease was best fit by an exponential model with half-maturity time constant of 5.1 days and asymptote of approximately -25.9 dB re:1.0 g/ms. Mean threshold approached within 3 dB of the asymptote by ages P6-P9. Similarly, response latencies decreased exponentially to within 3% of mature values at ages beyond P9. The half-maturity time constant for peripheral response peak latencies P1, N1, and P2 was comparable to thresholds and ranged from approximately 4.6 to 6.2 days, whereas central peaks (N2, P3, and N3) ranged from 2.9 to 3.4 days. Latency-intensity slopes for P1, N1, and P2 tended to decrease with age, reaching mature values within approximately 100 hours of hatching. Amplitudes increased as a function of age with average growth rates for response peaks ranging from 0.04 to 0.09 microV/day. There was no obvious asymptote to the growth of amplitudes over the ages studied. Amplitude-intensity slopes also increased modestly with age. The results show that gravity receptors are responsive to transient cranial stimuli as early as E19 in the chicken embryo. The functional response of gravity receptors continues to develop for many days after all major morphological structures are in place. Distinct maturational processes can be identified in central and peripheral neural relays. Functional improvements during maturation may result from refinements in the receptor epithelia, improvements in central and peripheral synaptic transmission, increased neural myelination, as well as changes in the mechanical coupling between the cranium and receptor organ.

Ontogeny of Vestibular Compound Action Potentials in the Domestic Chicken

PubMed Central

M. Jones, Sherri

2000-01-01

Compound action potentials of the vestibular nerve were measured from the surface of the scalp in 148 chickens (Gallus domesticus). Ages ranged from incubation day 18 (E18) to 22 days posthatch (P22). Responses were elicited using linear acceleration cranial pulses. Response thresholds decreased at an average rate of –0.45 dB/day. The decrease was best fit by an exponential model with half-maturity time constant of 5.1 days and asymptote of approximately –25.9 dB re:1.0 g/ms. Mean threshold approached within 3 dB of the asymptote by ages P6–P9. Similarly, response latencies decreased exponentially to within 3% of mature values at ages beyond P9. The half-maturity time constant for peripheral response peak latencies P1, N1, and P2 was comparable to thresholds and ranged from approximately 4.6 to 6.2 days, whereas central peaks (N2, P3, and N3) ranged from 2.9 to 3.4 days. Latency-intensity slopes for P1, N1, and P2 tended to decrease with age, reaching mature values within approximately 100 hours of hatching. Amplitudes increased as a function of age with average growth rates for response peaks ranging from 0.04 to 0.09 μV/day. There was no obvious asymptote to the growth of amplitudes over the ages studied. Amplitude-intensity slopes also increased modestly with age. The results show that gravity receptors are responsive to transient cranial stimuli as early as E19 in the chicken embryo. The functional response of gravity receptors continues to develop for many days after all major morphological structures are in place. Distinct maturational processes can be identified in central and peripheral neural relays. Functional improvements during maturation may result from refinements in the receptor epithelia, improvements in central and peripheral synaptic transmission, increased neural myelination, as well as changes in the mechanical coupling between the cranium and receptor organ. PMID:11545229

Assessing and evaluating multidisciplinary translational teams: a mixed methods approach.

PubMed

Wooten, Kevin C; Rose, Robert M; Ostir, Glenn V; Calhoun, William J; Ameredes, Bill T; Brasier, Allan R

2014-03-01

A case report illustrates how multidisciplinary translational teams can be assessed using outcome, process, and developmental types of evaluation using a mixed-methods approach. Types of evaluation appropriate for teams are considered in relation to relevant research questions and assessment methods. Logic models are applied to scientific projects and team development to inform choices between methods within a mixed-methods design. Use of an expert panel is reviewed, culminating in consensus ratings of 11 multidisciplinary teams and a final evaluation within a team-type taxonomy. Based on team maturation and scientific progress, teams were designated as (a) early in development, (b) traditional, (c) process focused, or (d) exemplary. Lessons learned from data reduction, use of mixed methods, and use of expert panels are explored.

The Behavioral Pediatrics Feeding Assessment Scale is a reliable and valid tool for Greek children.

PubMed

Sdravou, Katerina S L T; Evangeliou, Athanasios; Tentzidou, Kyriaki; Sotiriadou, Fotini; Stasinou, Eleanna; Fotoulaki, Maria

2018-05-11

Development of normal feeding is a highly complex sensorimotor process that depends upon the integration of neurological maturation, internal motivation and experiential learning (1-3). Disruption of the child's feeding process can lead to feeding problems during infancy and early childhood. One of the most widely used and validated scales for measuring whether a child's feeding problem has clinical significance is the Behavioral Pediatric Feeding Assessment Scale (BPFAS) (4). The objective of this study was to translate the BPFAS into Greek and culturally adapt the scale to evaluate the psychometric properties among the Greek parents of normally developing children. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Vacuolar processing enzyme plays an essential role in the crystalline structure of glutelin in rice seed.

PubMed

Kumamaru, Toshihiro; Uemura, Yuji; Inoue, Yoshimi; Takemoto, Yoko; Siddiqui, Sadar Uddin; Ogawa, Masahiro; Hara-Nishimura, Ikuko; Satoh, Hikaru

2010-01-01

To identify the function of genes that regulate the processing of proglutelin, we performed an analysis of glup3 mutants, which accumulates excess amounts of proglutelin and lack the vacuolar processing enzyme (VPE). VPE activity in developing seeds from glup3 lines was reduced remarkably compared with the wild type. DNA sequencing of the VPE gene in glup3 mutants revealed either amino acid substitutions or the appearance of a stop codon within the coding region. Microscopic observations showed that alpha-globulin and proglutelin were distributed homogeneously within glup3 protein storage vacuoles (PSVs), and that glup3 PSVs lacked the crystalline lattice structure typical of wild-type PSVs. This suggests that the processing of proglutelin by VPE in rice is essential for proper PSV structure and compartmentalization of storage proteins. Growth retardation in glup3 seedlings was also observed, indicating that the processing of proglutelin influences early seedling development. These findings indicate that storage of glutelin in its mature form as a crystalline structure in PSVs is required for the rapid use of glutelin as a source of amino acids during early seedling development. In conclusion, VPE plays an important role in the formation of protein crystalline structures in PSVs.

[The mammalian oviduct revisited].

PubMed

Halter, S; Reynaud, K; Tahir, Z; Thoumire, S; Chastant-Maillard, S; Saint-Dizier, M

2011-11-01

The oviducts, or uterine tubes, support the transport and final maturation of gametes, and harbour fertilization and early embryo development. The oviduct environment is finely regulated by ovarian steroids as well as by gametes and embryos that interact with it. Previously regarded as a simple transit zone, the oviduct is now regarded as a complex organ with multiple functions in these various processes. The tubal fluid, now better characterized, is to be regarded as the first interface between the mother and the embryo. It may play a major role in the quality of the conceptus. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Psychiatric/mental health nursing.

PubMed

DeSalvo Rankin, E A

1986-09-01

From a historical perspective, psychiatric/mental health nursing as a specialized area of practice is in its early developmental stages. Within the discipline of nursing and on the interdisciplinary scene, the range and scope of actions of the psychiatric/mental health specialists is still being debated. Professional roles and responsibilities are somewhat blurred. But the role is expanding. Contemporary psychiatric nursing practice has moved to a position of collegial support among the disciplines with shared responsibility. The attitudes of society, of the nursing profession, and of the health care providers will continue to influence the maturation process of the psychiatric/mental health nursing specialty.

More insights into early brain development through statistical analyses of eigen-structural elements of diffusion tensor imaging using multivariate adaptive regression splines

PubMed Central

Chen, Yasheng; Zhu, Hongtu; An, Hongyu; Armao, Diane; Shen, Dinggang; Gilmore, John H.; Lin, Weili

2013-01-01

The aim of this study was to characterize the maturational changes of the three eigenvalues (λ1 ≥ λ2 ≥ λ3) of diffusion tensor imaging (DTI) during early postnatal life for more insights into early brain development. In order to overcome the limitations of using presumed growth trajectories for regression analysis, we employed Multivariate Adaptive Regression Splines (MARS) to derive data-driven growth trajectories for the three eigenvalues. We further employed Generalized Estimating Equations (GEE) to carry out statistical inferences on the growth trajectories obtained with MARS. With a total of 71 longitudinal datasets acquired from 29 healthy, full-term pediatric subjects, we found that the growth velocities of the three eigenvalues were highly correlated, but significantly different from each other. This paradox suggested the existence of mechanisms coordinating the maturations of the three eigenvalues even though different physiological origins may be responsible for their temporal evolutions. Furthermore, our results revealed the limitations of using the average of λ2 and λ3 as the radial diffusivity in interpreting DTI findings during early brain development because these two eigenvalues had significantly different growth velocities even in central white matter. In addition, based upon the three eigenvalues, we have documented the growth trajectory differences between central and peripheral white matter, between anterior and posterior limbs of internal capsule, and between inferior and superior longitudinal fasciculus. Taken together, we have demonstrated that more insights into early brain maturation can be gained through analyzing eigen-structural elements of DTI. PMID:23455648

Prevention and anthropology.

PubMed

Jopp, Eilin; Scheffler, Christiane; Hermanussen, Michael

2014-01-01

Screening is an important issue in medicine and is used to early identify unrecognised diseases in persons who are apparently in good health. Screening strongly relies on the concept of "normal values". Normal values are defined as values that are frequently observed in a population and usually range within certain statistical limits. Screening for obesity should start early as the prevalence of obesity consolidates already at early school age. Though widely practiced, measuring BMI is not the ultimate solution for detecting obesity. Children with high BMI may be "robust" in skeletal dimensions. Assessing skeletal robustness and in particularly assessing developmental tempo in adolescents are also important issues in health screening. Yet, in spite of the necessity of screening investigations, appropriate reference values are often missing. Meanwhile, new concepts of growth diagrams have been developed. Stage line diagrams are useful for tracking developmental processes over time. Functional data analyses have efficiently been used for analysing longitudinal growth in height and assessing the tempo of maturation. Convenient low-cost statistics have also been developed for generating synthetic national references.

Comparative Proteomic Profiling Reveals Molecular Characteristics Associated with Oogenesis and Oocyte Maturation during Ovarian Development of Bactrocera dorsalis (Hendel)

PubMed Central

Li, Ran; Zhang, Meng-Yi; Liu, Yu-Wei; Zhang, Zheng; Smagghe, Guy; Wang, Jin-Jun

2017-01-01

Time-dependent expression of proteins in ovary is important to understand oogenesis in insects. Here, we profiled the proteomes of developing ovaries from Bactrocera dorsalis (Hendel) to obtain information about ovarian development with particular emphasis on differentially expressed proteins (DEPs) involved in oogenesis. A total of 4838 proteins were identified with an average peptide number of 8.15 and sequence coverage of 20.79%. Quantitative proteomic analysis showed that a total of 612 and 196 proteins were differentially expressed in developing and mature ovaries, respectively. Furthermore, 153, 196 and 59 potential target proteins were highly expressed in early, vitellogenic and mature ovaries and most tested DEPs had the similar trends consistent with the respective transcriptional profiles. These proteins were abundantly expressed in pre-vitellogenic and vitellogenic stages, including tropomyosin, vitellogenin, eukaryotic translation initiation factor, heat shock protein, importin protein, vitelline membrane protein, and chorion protein. Several hormone and signal pathway related proteins were also identified during ovarian development including piRNA, notch, insulin, juvenile, and ecdysone hormone signal pathways. This is the first report of a global ovary proteome of a tephritid fruit fly, and may contribute to understanding the complicate processes of ovarian development and exploring the potentially novel pest control targets. PMID:28665301

Ultrastructure of poison glands of South American frogs: a comparison between Physalaemus albonotatus and Leptodactylus chaquensis (Anura: Leptodactylidae).

PubMed

Alvarez, Blanca Beatriz; Delfino, Giovanni; Nosi, Daniele; Terreni, Alessandro

2005-02-01

Serous (poison) cutaneous glands of the leptodactylid species Physalaemus albonotatus and Leptodactylus chaquensis were compared using light and transmission electron microscopy. Glands in the two species share structural traits common in anurans, including the peripheral contractile sheath (myoepithelium) and the syncytial secretory unit that produces, stores, and modifies the poison. At the ultrastructural level, early steps of poison production are also similar and fit the usual path of proteosynthesis, involving rough endoplasmic reticulum (RER) and Golgi stacks (dictyosomes) in the peripheral syncytial cytoplasm. However, several differences are obvious during the maturational processes that lead post-Golgian products to their ultimate ultrastructural traits. In P. albonotatus, the dense product released from the dictyosomes acquires a thick repeating substructure, which, however, becomes looser in the inner portion of the syncytium. In L. chaquensis, serous maturation involves gradual condensation, and opaque, somewhat "vacuolized" granules are formed. These different maturational paths expressed during poison manufacturing in the two species agree with the polyphyletic origin of the family Leptodactylidae. On the other hand, data collected for P. albonotatus fit previous findings from P. biligonigerus and stress the view that poisons produced by congeneric species share similar (or identical) ultrastructural features. Copyright 2004 Wiley-Liss, Inc.

Influence of the indirect effects of guppies on life-history evolution in Rivulus hartii.

PubMed

Walsh, Matthew R; Reznick, David N

2010-06-01

Early theories of life-history evolution predict that increased predation on young/small individuals selects for delayed maturation and decreased reproductive effort, but such theory only considers changes in mortality. Predators reduce prey abundance and increase food to survivors. Theory that incorporates such indirect effects yields different predictions. Trinidadian killifish, Rivulus hartii, inhabit communities with and without guppies. Guppies prey on young Rivulus and Rivulus densities decline and growth rates increase when guppies are present. Prior work showed that Rivulus phenotypes from communities with guppies matured earlier and had higher fecundity, consistent with theories that incorporate indirect effects. Here we examined the genetic basis of these differences by rearing 2nd generation, laboratory-born Rivulus from sites with and without guppies under two food levels that match natural differences in growth. Many locality x food interactions were significant, often reversing the relationship between communities. Such interactions imply that there are fitness trade-offs associated with adaptation to high or low resource environments. On high food, Rivulus from localities with guppies matured earlier, produced many small eggs, and exhibited increased reproductive investment; these differences reversed on low food. Our results suggest that indirect effects mold Rivulus evolution and thereby highlight connections between community processes and evolutionary change.