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Sample records for basal mollusk wirenia

  1. Noodling for Mollusks

    ERIC Educational Resources Information Center

    Sukkestad, Kathryn; Curran, Mary Carla

    2012-01-01

    Mollusks, such as mussels and snails, are a great group to noodle because they are prevalent in banks and bottoms of river basins and in sandy beach habitats. Furthermore, their shells are easy to come by and safe to handle. There are six classes within the phylum Mollusca. In the activities described in this article, the authors focus on the…

  2. Invasion of the striped mollusks

    SciTech Connect

    Not Available

    1991-09-01

    Introduced to this country only five years ago, the prolific zebra mussel has infested the Great Lakes and has already begun to move into fresh waters beyond the region. Dense populations in utility water systems have caused serious problems, reducing plant efficiency and blocking lines used for cooling and fire fighting. Experts say the striped mollusk has the potential to become the industry's worst biological problem, possibly affecting 70% of US power plants. While it appears that the invader is here to stay, EPRI and others continue to develop and refine techniques to control mussel growth. This article describes how the mollusk got here, reviews the problems it can cause and what is being done to mitigate the problems and control the growth and spread of the mollusk.

  3. RECENT BIOGENIC PHOSPHORITE: CONCRETIONS IN MOLLUSK KIDNEYS

    EPA Science Inventory

    Phosphorite concretions have been detected in the kidneys of two widespread species of mollusks. Mercenaria mercenaria and Argopecten irradians, which have relatively high population densities. These concretions are the first documentation of the direct biogenic formation of phos...

  4. Rostroconchia: A new class of bivalved mollusks

    USGS Publications Warehouse

    Pojeta, J., Jr.; Runnegar, B.; Morris, N.J.; Newell, N.D.

    1972-01-01

    Four Paleozoic bivalved genera are assigned to the new molluscan class Rostroconchia: Eopteria, Euchasma, Conocardium, and Pseudoconocardium. These mollusks have an uncoiled univalved larval shell; an untorted bivalved adult shell; no hinge teeth, ligament, or adductor muscles; and a fused, almost inflexible, hinge. Rostroconchians developed separately from the pelecypods through the ribeirioids, but are regarded as more closely related to the Pelecypoda and Scaphopoda than to other known classes of molllusks.

  5. Carbon isotopes in mollusk shell carbonates

    NASA Astrophysics Data System (ADS)

    McConnaughey, Ted A.; Gillikin, David Paul

    2008-10-01

    Mollusk shells contain many isotopic clues about calcification physiology and environmental conditions at the time of shell formation. In this review, we use both published and unpublished data to discuss carbon isotopes in both bivalve and gastropod shell carbonates. Land snails construct their shells mainly from respired CO2, and shell δ13C reflects the local mix of C3 and C4 plants consumed. Shell δ13C is typically >10‰ heavier than diet, probably because respiratory gas exchange discards CO2, and retains the isotopically heavier HCO3 -. Respired CO2 contributes less to the shells of aquatic mollusks, because CO2/O2 ratios are usually higher in water than in air, leading to more replacement of respired CO2 by environmental CO2. Fluid exchange with the environment also brings additional dissolved inorganic carbon (DIC) into the calcification site. Shell δ13C is typically a few ‰ lower than ambient DIC, and often decreases with age. Shell δ13C retains clues about processes such as ecosystem metabolism and estuarine mixing. Ca2+ ATPase-based models of calcification physiology developed for corals and algae likely apply to mollusks, too, but lower pH and carbonic anhydrase at the calcification site probably suppress kinetic isotope effects. Carbon isotopes in biogenic carbonates are clearly complex, but cautious interpretation can provide a wealth of information, especially after vital effects are better understood.

  6. Recent biogenic phosphorite: Concretions in mollusk kidneys

    USGS Publications Warehouse

    Doyle, L.J.; Blake, N.J.; Woo, C.C.; Yevich, P.

    1978-01-01

    Phosphorite concretions have been detected in the kidneys of two widespread species ofmollusks, Mercenaria mercenaria and Argopecten irradians, which have relatively high population densities. These concretions are thefirst documentation of the direct biogenic formation of phosphorite grains. The concretions are principally amorphous calcium phosphate, which upon being heated yields an x-ray diffraction pattern which is essentially that of chlorapatite. These concretions appear to be a normal formation of the excretory process of mollusks under reproductive, environmental, or pollutant-induced stress. Biogenic production of phosphorite concretions over long periods of time and diagenetic change from amorphous to crystalline structure, coupled with secondary enrichment, may account for the formation of some marine phosphorite desposits which are not easily explained by the chemical precipitation- replacement hypothesis. Copyright ?? 1978 AAAS.

  7. The microindentation behavior of several mollusk shells

    SciTech Connect

    Laraia, V.J.; Heuer, A.H. . Dept. of Materials Science and Engineering)

    1990-01-01

    An investigation of the relationship between structure and mechanical behavior is reported for mollusk shells employing foliated, nacreous, and crossed-lamellar structures by microindentation in the Knoop and Vickers geometries. Indentation damage zones develop crack systems that reflect the micro-architecture. For the crosed-lamellar structure, the system of cracks about the indentation normally developed in a brittle material is suppressed. Previous reports that shells are harder than the corresponding minerals, calcite and aragonite, are confirmed, but it is found that this effect can be strongly dependent on orientation. This anomalous hardness is not an artifact of the indentation test technique, since scratch tests confirm the relative hardness of shell over the mineral. It is suggested that microstructural organization is of central importance in producing this hardness, as opposed to intrinsic properties of the mineral or matrix phases. 17 refs., 6 figs., 1 tab.

  8. Hemocyanin respiratory pigment in bivalve mollusks

    SciTech Connect

    Morse, M.P.; Meyhoefer, E.; Otto, J.J.; Kuzirian, A.M.

    1986-03-14

    Hemocyanins, high molecular weight oxygen-binding proteins, were identified in two species of protobranch bivalve mollusks, Acila castrensis and Yoldia limatula. Although hemocyanins have been reported in chitons, gastropods, and cephalopods, they have not been observed in the Class Bivalvia. In A. castrensis the dissociation products of hemocyanin, characterized by gel electrophoresis, had a subunit molecular weight of approximately 250K. Negatively stained preparations of extracted hemocyanin formed protein aggregates in the shape of cylinders measuring 35 by 38 nanometers. X-ray microanalysis of hemocyanin aggregates in thin sections of Y. limatula demonstrated the presence of copper in the molecules. The discovery of hemocyanin in the protobranchs reinforces the primitive nature of the taxon and is further evidence that the major molluscan classes have a common ancestry. 14 references, 3 figures.

  9. Cumberlandian Mollusk Conservation Program. Activity 2: potential fish hosts

    SciTech Connect

    Koch, L.M.; Hickman, G.D.; Swor, C.T.

    1986-02-01

    Fish species from sand/gravel substrates and from rubble substrates which are the most likely hosts for Cumberlandian mussel fauna, C. caelata and Q. intermedia, from the Clinch, Duck, Elk, and Powell Rivers are reported. Infection with mollusk glochidia was used with overlap and occurrences to develop a ranking of each species potential as a suitable host for Cumberlandian mollusks. 12 ref., 4 figs., 9 tabs.

  10. Closed recirculating system for shrimp-mollusk polyculture

    NASA Astrophysics Data System (ADS)

    Wu, Xiongfei; Zhao, Zhidong; Li, Deshang; Chang, Kangmei; Tong, Zhuanshang; Si, Liegang; Xu, Kaichong; Ge, Bailin

    2005-12-01

    This paper deals with a new system of aquaculture, i.e., a closed recirculating system for shrimp-mollusk polyculture. The culture system consisted of several shrimp ponds, a mollusk water-purifying pond and a reservoir. During the production cycle, water circulated between the shrimp and mollusk ponds, and the reservoir compensated for water loss from seepage and evaporation. Constricted tagelus, Sinonovacula constricta, was selected as the cultured mollusk, and Pacific white shrimp, Litopenaeus vannamei, as the cultured shrimp. The main managing measures during the production cycle were: setting and using the aerators; introducting the probiotic products timely into the shrimp ponds; adopting a “pen-closing” method for controlling shrimp viral epidemics; setting the flow diversion barriers in the mollusk pond to keep the circulating water flowing through the pond along a sine-like curve and serve as substrate for biofilm; no direct feeding was necessary for the cultured mollusk until the co-cultured shrimp was harvested; natural foods in the water from the shrimp ponds was used for their foods. Two sets of the system were used in the experiment in 2002 and satisfactory results were achieved. The average yield of the shrimp was 11 943.5 kg/hm2, and that of the mollusk was 16 965 kg/hm2. After converting the mollusk yield into shrimp yield at their market price ratio, the food coefficient of the entire system averaged at as low as 0.81. The water quality in the ponds was maintained at a desirable level and no viral epidemics were discovered during the production cycle.

  11. Diversity of the RFamide Peptide Family in Mollusks

    PubMed Central

    Zatylny-Gaudin, Celine; Favrel, Pascal

    2014-01-01

    Since the initial characterization of the cardioexcitatory peptide FMRFamide in the bivalve mollusk Macrocallista nimbosa, a great number of FMRFamide-like peptides (FLPs) have been identified in mollusks. FLPs were initially isolated and molecularly characterized in model mollusks using biochemical methods. The development of recombinant technologies and, more recently, of genomics has boosted knowledge on their diversity in various mollusk classes. Today, mollusk FLPs represent approximately 75 distinct RFamide peptides that appear to result from the expression of only five genes: the FMRFamide-related peptide gene, the LFRFamide gene, the luqin gene, the neuropeptide F gene, and the cholecystokinin/sulfakinin gene. FLPs display a complex spatiotemporal pattern of expression in the central and peripheral nervous system. Working as neurotransmitters, neuromodulators, or neurohormones, FLPs are involved in the control of a great variety of biological and physiological processes including cardiovascular regulation, osmoregulation, reproduction, digestion, and feeding behavior. From an evolutionary viewpoint, the major challenge will then logically concern the elucidation of the FLP repertoire of orphan mollusk classes and the way they are functionally related. In this respect, deciphering FLP signaling pathways by characterizing the specific receptors these peptides bind remains another exciting objective. PMID:25386166

  12. Cumberlandian Mollusk Conservation Program. Activity 1: mussel distribution surveys

    SciTech Connect

    Ahlstedt, S.A.

    1986-01-01

    The distribution of Cumberlandian mollusks in the Tennessee Valley is one of nine research activities developed as part of TVA's Cumberlandian Mollusk Conservation Program (CMCP). The name Cumberlandian refers to an endemic faunal assemblage that encompasses portions of 7 states bordering the southern Appalachian Mountains and the Cumberland Plateau Region. This geographic region is known as one of the major centers for mussel speciation and is considered the most prolific areas of the world for this particular group of organisms. Nine Tennessee Valley streams were selected for intensive qualitative and quantitative mussel surveys under Activity I of the CMCP. The surveys were designed to gather information on the present distribution of Cumberlandian mollusks. The streams chosen for surveys were based on the documented presence of diverse mussel fauna, endangered mussels, and/or sufficient information (diverse fish fauna, good water quality, etc.) to suggest potential for occurrence of diverse mussel fauna or endangered species.

  13. CHEMICAL CARCINOGENS IN BIVALVE MOLLUSKS FROM OREGON ESTUARIES

    EPA Science Inventory

    The research undertaken involved the use of indigenous populatons of bivalve mollusks as monitors for detecting and quantifying environmental benzo(s)pyrene (BAP) in Oregon estuaries. Short-term and long-term studies were conducted in order to establish baseline levels of BAP and...

  14. Mollusks of Candomblé: symbolic and ritualistic importance.

    PubMed

    Léo Neto, Nivaldo A; Voeks, Robert A; Dias, Thelma L P; Alves, Rômulo R N

    2012-01-01

    Human societies utilize mollusks for myriad material and spiritual ends. An example of their use in a religious context is found in Brazil's African-derived belief systems. Candomblé, an Afro-Brazilian religion introduced during the 18th-19th centuries by enslaved Yoruba, includes various magical and liturgical uses of mollusks. This work inventoried the species utilized by adherents and to analyzed their symbolic and magical context. Data were obtained from Candomblé temples in two cities in the northeast of Brazil-Caruaru, in the state of Pernambuco, and Campina Grande, in the state of Paraíba. Questionnaires administered to eleven adepts revealed that at least nineteen mollusk species are being used. Shells from Monetaria moneta, M. annulus and Erosaria caputserpentis were cited by all of the interviewees. Three uses stood out: divination (jogo de búzios); utilization as ritual objects; and employment as sacrificial offerings (Igbin or Boi-de-Oxalá). The jogo de búzios (shell toss), employed in West Africa, Brazil and Cuba, is of fundamental importance to the cult, representing the means by which the faithful enter in contact with the divinities (Orixás) and consult people's futures (Odu). The utilization of mollusks in Candomblé is strongly influenced by ancient Yoruba myths (Itãs) which, having survived enslavement and generations of captive labor, continue to guide the lives of Brazil's African Diaspora. PMID:22420523

  15. Mollusks of Candomblé: symbolic and ritualistic importance

    PubMed Central

    2012-01-01

    Human societies utilize mollusks for myriad material and spiritual ends. An example of their use in a religious context is found in Brazil's African-derived belief systems. Candomblé, an Afro-Brazilian religion introduced during the 18th-19th centuries by enslaved Yoruba, includes various magical and liturgical uses of mollusks. This work inventoried the species utilized by adherents and to analyzed their symbolic and magical context. Data were obtained from Candomblé temples in two cities in the northeast of Brazil-Caruaru, in the state of Pernambuco, and Campina Grande, in the state of Paraíba. Questionnaires administered to eleven adepts revealed that at least nineteen mollusk species are being used. Shells from Monetaria moneta, M. annulus and Erosaria caputserpentis were cited by all of the interviewees. Three uses stood out: divination (jogo de búzios); utilization as ritual objects; and employment as sacrificial offerings (Igbin or Boi-de-Oxalá). The jogo de búzios (shell toss), employed in West Africa, Brazil and Cuba, is of fundamental importance to the cult, representing the means by which the faithful enter in contact with the divinities (Orixás) and consult people's futures (Odu). The utilization of mollusks in Candomblé is strongly influenced by ancient Yoruba myths (Itãs) which, having survived enslavement and generations of captive labor, continue to guide the lives of Brazil's African Diaspora. PMID:22420523

  16. Detection, isolation, and persistence of viruses within bivalve mollusks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Norovirus (NV), hepatitis A virus (HAV), and other virus transmission by molluscan shellfish is a significant issue. Research at the ARS-Dover DE laboratory has led to the development of improved methods for detecting these viruses. To identify pathogenic viruses within mollusks, a rapid highly-se...

  17. Anthropogenic effects on marine mollusks diversity and abundance; mangrove mollusks along an environmental gradient at Teyab, Persian gulf

    NASA Astrophysics Data System (ADS)

    Azarmanesh, H.; Javanshir, A.

    2009-04-01

    Management of coastal environments requires understanding of ecological relationships among different habitats and their biotas.. The mollusk diversity and density and sedimentological properties of mangrove (Avicennia marina) stands of two different seasons in Teyab have been compared. Pollutant area and cleaner area showed clear separation on the basis of environmental characteristics and benthic mollusks. Numbers of mollusks taxa were generally larger at cleaner sites, and numbers of individuals of several taxa were also larger at other sites. The total number of individuals was not different between the two seasons, largely due to the presence of large numbers of the Mud-living gastropod Cerithium cingulata at the pollutant sites. Differences in the Mollusks were coincident with differences in the nature of the sediment. Sediments in cleaner stands were more compacted and contained lesser organic matter and leaf litter.Analysis of sediment chemistry suggested that mangrove sediment in the Cleaner sites were able to take up more N and P than those in the other sites. Key Words: Sustainable development, Impact, Gastropods, Bivalves, Persian Gulf

  18. Basal Cell Carcinoma (BCC)

    MedlinePlus

    ... carcinomas: Infiltrating basal cell carcinomas can be more aggressive and locally destructive than other types of basal ... to treat them early and with slightly more aggressive techniques. Excision – The basal cell carcinoma is cut ...

  19. Mollusk shell nacre ultrastructure correlates with environmental temperature and pressure.

    PubMed

    Olson, Ian C; Kozdon, Reinhard; Valley, John W; Gilbert, Pupa U P A

    2012-05-01

    Nacre, or mother-of-pearl, the tough, iridescent biomineral lining the inner side of some mollusk shells, has alternating biogenic aragonite (calcium carbonate, CaCO(3)) tablet layers and organic sheets. Nacre has been common in the shells of mollusks since the Ordovician (450 million years ago) and is abundant and well-preserved in the fossil record, e.g., in ammonites. Therefore, if any measurable physical aspect of the nacre structure was correlated with environmental temperatures, one could obtain a structural paleothermometer of ancient climates. Using X-ray absorption near-edge structure (XANES) spectroscopy, Photoelectron emission spectromicroscopy (PEEM), and X-ray linear dichroism we acquired polarization-dependent imaging contrast (PIC) maps of pristine nacre in cross-section. The new PIC-map data reveal that the nacre ultrastructure (nacre tablet width, thickness, and angle spread) is species-specific in at least eight mollusk species from completely different environments: Nautilus pompilius, Haliotis iris, Haliotis rufescens, Bathymodiolus azoricus, Atrina rigida, Lasmigona complanata, Pinctada margaritifera, and Mytilus californianus. Nacre species-specificity is interpreted as a result of adaptation to diverging environments. We found strong correlation between nacre crystal misorientations and environmental temperature, further supported by secondary ion mass spectrometry measurements of in situ δ(18)O in the nacre of one shell. This has far-reaching implications: nacre texture may be used as a paleothermometer of ancient climate, spanning 450 million years of Earth's history. PMID:22313180

  20. Effects of contaminants on naiad mollusks (Unionidae): a review

    USGS Publications Warehouse

    Havlik, M.E.; Marking, L.L.

    1987-01-01

    Although the uptake, storage, and elimination of contaminants by naiad mollusks has been studied, relatively little information is available on toxicity. Contaminants appear to have destroyed some populations directly by exerting toxic effects, or indirectly by causing or contributing to the elimination of essential food organisms or host fish. The most frequently studied contaminants are Cd, Cu, Mn-Mn64, Pb-Pb210. and Zn-Zn65. Manganese seems to be most readily taken up and stored in tissues; no apparent damage has been reported from tissue concentrations of thousands of parts per million (ppm) and the element appears to be essential to metabolism. Zinc and cadmium also accumulate at high levels in tissues. Lead was never found to be lethal in the studies reviewed. Various common contaminants have been reported to be toxic at the following concentrations (ppm): cadmium. 2; copper sulfate, 2 to 18.7; ammonia, 5; potassium. 11; chromium, 12.4; arsenic trioxide, 16; copper, 19; and zinc, 66. In long-term exposures, concentrations of copper as low as 25 parts per billion (ppb) were lethal. Fry of fish infected with 20-35 glochidia were more sensitive than uninfected fish to toluene, naphthalene, and crude oil. Although few specific adverse impacts of contaminants have become clearly evident, circumstantial evidence leaves little doubt that contaminants have been responsible for decreases in population density, range, and diversity. Stresses that have been responsible for the disappearance of naiad mollusks in contaminated areas have not generally been identified, and the components of the stresses have seldom been quantitatively and qualitatively correlated with the composition and size of the naiad fauna. Often two or more factors appear to work in combination to produce the total stress that adversely affects populations. Naiad mollusks are important indio caters of contaminants in the environment; residues in soft tissue indicate recent or current exposure, and

  1. Mid-Neolithic Exploitation of Mollusks in the Guanzhong Basin of Northwestern China: Preliminary Results

    PubMed Central

    Li, Fengjiang; Wu, Naiqin; Lu, Houyuan; Zhang, Jianping; Wang, Weilin; Ma, Mingzhi; Zhang, Xiaohu; Yang, Xiaoyan

    2013-01-01

    Mollusk remains are abundant in archaeological sites in the Guanzhong Basin of Northwestern China, providing good opportunities for investigations into the use of mollusks by prehistoric humans. Here we report on freshwater gastropod and bivalve mollusks covering the time interval from about 5600 to 4500 cal. yrs BP from sites of Mid-Late Neolithic age. They are identified as Cipangopaludina chinensis and Unio douglasiae, both of which are currently food for humans. The shells are well preserved and have no signs of abrasion. They are all freshwater gastropods and bivalves found in pits without water-reworked deposits and have modern representatives which can be observed in rivers, reservoirs, and paddy fields in the studied region. Mollusk shells were frequently recovered in association with mammal bones, lithic artifacts, and pottery. These lines of evidence indicate that the mollusks are the remains of prehistoric meals. The mollusk shells were likely discarded into the pits by prehistoric humans after the flesh was eaten. However, these mollusk remains may not have been staple food since they are not found in large quantities. Mollusk shell tools and ornaments are also observed. Shell tools include shell knives, shell reaphooks and arrowheads, whereas shell ornaments are composed of pendants and loops. All the shell tools and ornaments are made of bivalve mollusks and do not occur in large numbers. The finding of these freshwater mollusk remains supports the view that the middle Holocene climate in the Guanzhong Basin may have been warm and moist, which was probably favorable to freshwater mollusks growing and developing in the region. PMID:23544050

  2. Mid-Neolithic exploitation of mollusks in the Guanzhong Basin of Northwestern China: preliminary results.

    PubMed

    Li, Fengjiang; Wu, Naiqin; Lu, Houyuan; Zhang, Jianping; Wang, Weilin; Ma, Mingzhi; Zhang, Xiaohu; Yang, Xiaoyan

    2013-01-01

    Mollusk remains are abundant in archaeological sites in the Guanzhong Basin of Northwestern China, providing good opportunities for investigations into the use of mollusks by prehistoric humans. Here we report on freshwater gastropod and bivalve mollusks covering the time interval from about 5600 to 4500 cal. yrs BP from sites of Mid-Late Neolithic age. They are identified as Cipangopaludina chinensis and Unio douglasiae, both of which are currently food for humans. The shells are well preserved and have no signs of abrasion. They are all freshwater gastropods and bivalves found in pits without water-reworked deposits and have modern representatives which can be observed in rivers, reservoirs, and paddy fields in the studied region. Mollusk shells were frequently recovered in association with mammal bones, lithic artifacts, and pottery. These lines of evidence indicate that the mollusks are the remains of prehistoric meals. The mollusk shells were likely discarded into the pits by prehistoric humans after the flesh was eaten. However, these mollusk remains may not have been staple food since they are not found in large quantities. Mollusk shell tools and ornaments are also observed. Shell tools include shell knives, shell reaphooks and arrowheads, whereas shell ornaments are composed of pendants and loops. All the shell tools and ornaments are made of bivalve mollusks and do not occur in large numbers. The finding of these freshwater mollusk remains supports the view that the middle Holocene climate in the Guanzhong Basin may have been warm and moist, which was probably favorable to freshwater mollusks growing and developing in the region. PMID:23544050

  3. Diagenetic changes in the elemental composition of unrecrystallized mollusk shells

    USGS Publications Warehouse

    Ragland, P.C.; Pilkey, O.H.; Blackwelder, B. W.

    1979-01-01

    The Mg, Sr, Mn, Fe, Na and K contents were determined for 230 apparently unrecrystallized mollusk shells (gastropods and bivalves) ranging in age from late Cretaceous to Holocene. Consistent differences between the Holocene and fossil shells with respect to concentrations of all these elements are attributed to postburial diagenetic changes. Fossil-Holocene shell comparisons are made on the intergeneric level, a more severe test of compositional differences than was previous work involved with few species. The observed differences re-emphasize the need for extreme caution in the use of the many geochemical tools which assume that no compositional changes have taken place prior to recrystallization of calcareous materials. ?? 1979.

  4. The organic-mineral interaction in mollusk shell

    NASA Astrophysics Data System (ADS)

    Metzler, Rebecca A.

    Macromolecules are a minority but important component of the minerals formed by living organisms, or biominerals. While many proteins from the nacre and prismatic layers of mollusk shells have been identified and sequenced, the molecular interaction, organization, and rearrangements of proteins upon organic-mineral bond formation, and the effect of this interaction on crystal formation, deformation, and orientation are poorly understood. To examine the organic-mineral interaction in mollusk shells, we prepared model systems consisting of calcium carbonate grown in the presence of synthetic mollusk shell polypeptides. X-ray absorption near-edge structure (XANES) spectroscopy and x-ray photoelectron emission microscopy (X-PEEM) were used to examine the electronic structure and bonding environment of both the surface and bulk of model biomineral crystals, thereby determining that the organic-mineral interaction is a series of events starting with bond formation and ending with the fully formed mineral. XANES spectra acquired from the model biomineral systems showed that upon organic-mineral bond formation both the crystal and the polypeptides exhibit bond and molecular structure alterations. We acquired XANES spectra from the surface of calcium carbonate crystals grown in the presence of six synthetic polypeptides sequenced after mollusk nacre proteins: AP7N, AP24N, N16N, asp1, asp2, and ACCN. All of these model biominerals gave similar results, namely the disruption of CO bonds in calcite and enhancement of the peaks associated with C-H bonds bonds in peptides, indicating disordering of the calcite crystal and ordering of the peptides upon binding. We also show that these changes do not occur when the acidic amino acids, Asp and Glu, are replaced in the N16N sequence with Asn and Gln, respectively, demonstrating the importance of carboxyl groups in organic-mineral bond formation. We examined the bulk crystal structure of crystals grown in the presence of N16N and asp

  5. Characterization of acidic polysaccharides from the mollusks through acid hydrolysis.

    PubMed

    Cao, Jiuling; Wen, Chengrong; Lu, Jiaojiao; Teng, Nan; Song, Shuang; Zhu, Beiwei

    2015-10-01

    Uronic acid-containing polysaccharides (UACPs) including glycosaminoglycans (GAGs) exist widely in nature. Herein we propose an elegant methodology to identify UACPs by analyzing their disaccharides produced from the acid hydrolysis using HPLC-MS(n) upon 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization. Based on the optimization of experimental conditions by the single factor experiment and orthogonal test design, the combination of 1.3M TFA at 105°C for 3h is found to be the optimum. Subsequently, these conditions were applied to investigate the distribution of UACPs in 20 selected species of edible Bivalvia and Gastropoda. PMP-disaccharides derived from UACPs in mollusks were identified by comparing the retention time and mass spectra with those of the reference PMP-disaccharides from hyaluronic acid (HA), chondroitin sulfate (CS), heparin (HP), and AGSP with →4)-GlcA(1→2)-Man(1→ repeating units. The analysis reveals the prevalence of CS in the shellfishes as well as the HP, and existence of three non-GAG UACPs in 7 mollusks. PMID:26076626

  6. What can a sessile mollusk tell about neotectonics?

    NASA Astrophysics Data System (ADS)

    Sivan, D.; Schattner, U.; Morhange, C.; Boaretto, E.

    2010-08-01

    Dendropoma petraeum are fixed vermitids (mollusk) that colonize and construct abrasion platform rims along rocky shorelines. These endemic mollusks are considered good relative sea level indicators in the eastern and the southern Mediterranean, due to their narrow habitat below the sea surface (about ±10 cm). The observed relative sea level values recorded (submerged, uplifted or at present mean sea level) reflect a superposition of eustatic, isostatic, tectonic and possibly local sedimentary instabilities. The present study examines fossil Dendropoma samples gathered along the Levant coast, from northern Israel to eastern Turkey. Conventional radiocarbon dates (from Turkey, Syria and partly in Lebanon) and 14C Accelerator Mass Spectrometer (AMS) from Lebanon and Israel yields Dendropoma ages ranging through Late Holocene. A numerical model is used for calculating the change in sea level through the Holocene as a function of glacio-hydrology and isostasy of the eastern Mediterranean. Space-time dependent subtractions of the model values are used to eliminate the eustatic component of the relative sea level, in order to obtain the tectonic component. Results show a general northward increase in tectonic uplift of the Levantine coast with different rates in different tectonic segments. This differential uplift corresponds well to the major tectonic segments comprising the Levantine continental margin since the Pleistocene, from the Carmel fault to the East Anatolian fault. Hence, these segments were still active during the last thousands years and even during the last hundreds years. The general trend of northward increase in vertical displacement is predominantly dictated by the convergence between the Sinai and Arabian plates with Anatolia and Eurasia, across the Cyprus arc and Zagros belt; and the secondarily dictated by the northward increase in convergence component across the sinistral Dead Sea Fault plate boundary.

  7. Salinity and Temperature Tolerance Experiments on Selected Florida Bay Mollusks

    USGS Publications Warehouse

    Murray, James B.; Wingard, G. Lynn

    2006-01-01

    The ultimate goal of the Comprehensive Everglades Restoration Plan (CERP) is to restore and preserve the unique ecosystems of South Florida, including the estuaries. Understanding the effect of salinity and temperature changes, beyond typical oscillations, on the biota of South Florida's estuaries is a necessary component of achieving the goal of restoring the estuaries. The U.S. Geological Survey has been actively involved in researching the history of the South Florida Ecosystem, to provide targets, performance measures, and baseline data for restoration managers. These experiments addressed two aspects of ecosystem history research: 1) determining the utility of using molluscan shells as recorders of change in water chemistry parameters, primarily salinity, and 2) enhancing our in situ observations on modern assemblages by exceeding typically observed aquatic conditions. This set of experiments expanded our understanding of the effects of salinity, temperature and other water chemistry parameters on the reproduction, growth and overall survivability of key species of mollusks used in interpreting sediment core data. Observations on mollusks, plants and microbes made as part of these experiments have further refined our knowledge and understanding of the effects of ecosystem feedback and the role salinity and temperature play in ecosystem stability. The results have demonstrated the viability of several molluscan species as indicators of atypical salinity, and possibly temperature, modulations. For example Cerithium muscarum and Bulla striata demonstrated an ability to withstand a broad salinity and temperature range, with reproduction occurring in atypically high salinities and temperatures. These experiments also provided calibration data for the shell biogeochemistry of Chione cancellata and the possible use of this species as a water chemistry recorder. Observations made in the mesocosms, on a scale not normally observable in the field, have led to new

  8. Autoimmune basal ganglia disorders.

    PubMed

    Dale, Russell C; Brilot, Fabienne

    2012-11-01

    The basal ganglia are deep nuclei in the brain that include the caudate, putamen, globus pallidus, and substantia nigra. Pathological processes involving the basal ganglia often result in disorders of movement and behavior. A number of different autoimmune disorders predominantly involve the basal ganglia and can result in movement and psychiatric disorders. The classic basal ganglia autoimmune disorder is Sydenham chorea, a poststreptococcal neuropsychiatric disorder. Resurgence in the interest in Sydenham chorea is the result of the descriptions of other poststreptococcal neuropsychiatric disorders including tics and obsessive-compulsive disorder, broadly termed pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection. Encephalitic processes affecting the basal ganglia are also described including the syndromes basal ganglia encephalitis, encephalitis lethargica, and bilateral striatal necrosis. Last, systemic autoimmune disorders such as systemic lupus erythematosus and antiphospholipid syndrome can result in chorea or parkinsonism. Using paradigms learned from other autoantibody associated disorders, the authors discuss the autoantibody hypothesis and the role of systemic inflammation in autoimmune basal ganglia disorders. Identification of these entities is important as the clinician has an increasing therapeutic repertoire to modulate or suppress the aberrant immune system. PMID:22832771

  9. Design-based and model-based inference in surveys of freshwater mollusks

    USGS Publications Warehouse

    Dorazio, R.M.

    1999-01-01

    Well-known concepts in statistical inference and sampling theory are used to develop recommendations for planning and analyzing the results of quantitative surveys of freshwater mollusks. Two methods of inference commonly used in survey sampling (design-based and model-based) are described and illustrated using examples relevant in surveys of freshwater mollusks. The particular objectives of a survey and the type of information observed in each unit of sampling can be used to help select the sampling design and the method of inference. For example, the mean density of a sparsely distributed population of mollusks can be estimated with higher precision by using model-based inference or by using design-based inference with adaptive cluster sampling than by using design-based inference with conventional sampling. More experience with quantitative surveys of natural assemblages of freshwater mollusks is needed to determine the actual benefits of different sampling designs and inferential procedures.

  10. Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks

    USGS Publications Warehouse

    Turgeon, D. D.; Quinn, J.F.; Bogan, A.E.; Coan, E. V.; Hochberg, F.G.; Lyons, W.G.; Mikkelsen, P. M.; Neves, R.J.; Roper, C. F. E.; Rosenberg, G.; Roth, B.; Scheltema, A.; Thompson, F.G.; Vecchione, M.; Williams, J.D.

    1998-01-01

    This edition of Common and Scientific Names of Invertebrates from the United States and Canada: Mollusks represents the efforts of 15 molluscan taxonomic specialists in compiling a comprehensive checklist of the mollusks found in North America and Canada and their vernacular names. Built upon the success of the first edition, the authors have updated the nomenclature to reflect recent phylogenetic analyses and have included more than 300 new species.

  11. Organochlorine Pesticides in Consumer Fish and Mollusks of Liaoning Province, China: Distribution and Human Exposure Implications

    PubMed Central

    Zhang, Hongmei; Tao, Minhui; Yang, Shaobin; Wang, Liwei; Liu, Ying; Ma, Dandan; He, Zhiming

    2010-01-01

    Fish and mollusk samples were collected from markets located in 12 cities in Liaoning province, China, during August and September 2007, and 22 organochlorine pesticides (OCPs) were detected. DDT, HCH, endosulfan, chlordane, and HCB were the dominating OCPs, with mean concentrations and ranges of, respectively, 15.41 and 0.57 to 177.56 ng/g, 0.84 and below detection limit (BDL) to 22.99 ng/g, 1.31 and BDL to 13.1 ng/g, 1.05 and BDL to 15.68 ng/g, and 0.63 and BDL to 9.21 ng/g in all fish and mollusk samples. The concentrations of other OCPs generally were low and were detectable in a minority of samples, reflecting the low levels of these OCPs in the study region. In general, OCP concentrations were obviously higher in fish than in mollusks, and higher in freshwater fish than in marine fish, which indicated, first, that freshwater fish are more easily influenced than seawater fish and mollusks by OCP residues in agricultural areas and, second, that there are different biota accumulation factors for OCPs between fish and mollusk. To learn the consumption of fish and mollusk, 256 questionnaires were sent to families in 12 cities of Liaoning province. Using the contamination data, average estimated daily intakes of OCPs via fish and mollusk consumption were calculated, which were used for exposure assessment. The public health risks caused by exposure to OCPs in the course of fish and mollusk consumption were compared to noncancer benchmarks and cancer benchmarks. PMID:20352204

  12. Risk Assessment of Organochlorines in Mollusk from the Mediterranean and Red Sea Coasts of Egypt.

    PubMed

    El Nemr, Ahmed; El-Said, Ghada F; Khaled, Azza

    2016-04-01

    Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) residues were studied in different mollusk species from the Egyptian Mediterranean and Red Sea coasts. The average levels of OCPs in mollusks comprised chlordanes, dieldrins, total endrin, endosulfan compounds, and methoxychlor (DECEM), dichlorodiphenyltrichloroethanes (DDTs), and, hexachlorocyclohexanes (HCHs). The averages of HCHs, DDTs, and polychlorinated biphenyls (PCBs) in mollusks from the Mediterranean Sea were 1.13±1.21, 1.30±1.27, and 1.40±0.93 ng/g, respectively; from the Red Sea, they were 0.62±0.90, 1.77±1.82, and 6.44±5.05 ng/g, respectively. The analysis of HCHs, DDTs, and PCBs in mollusks indicates a new usage of lindane, PCB congeners, and the input of technical HCH and aged DDT. The data showed that the Red Sea Coast was more affected by PCBs congeners than the Mediterranean Sea Coast, which may be attributed to the different activities along the two coastal areas. Mollusks in the Mediterranean Sea had higher dieldrins, total endrin, endosulfan compounds, and methoxychlor contents than those in the Red Sea. Interestingly, HCHs, DDTs, and PCBs levels were lower than those recommended for Swedish Food Regulation and U.S. Food and Drug Administration, which means that mollusks from these two coastal areas are safe as food. PMID:27131056

  13. Basal cell cancer (image)

    MedlinePlus

    ... is needed to prove the diagnosis of basal cell carcinoma. Treatment varies depending on the size, depth, and location of the cancer. Early treatment by a dermatologist may result in a cure rate of more than 95%, but regular examination ...

  14. Basal cell skin cancer

    MedlinePlus

    ... occur in younger people who have had extensive sun exposure. You are more likely to get basal cell ... severe sunburns early in life Long-term daily sun exposure (such as the sun exposure received by people ...

  15. Basal Cell Carcinoma

    PubMed Central

    Lanoue, Julien

    2016-01-01

    Basal cell carcinoma is the most commonly occurring cancer in the world and overall incidence is still on the rise. While typically a slow-growing tumor for which metastases is rare, basal cell carcinoma can be locally destructive and disfiguring. Given the vast prevalence of this disease, there is a significant overall burden on patient well-being and quality of life. The current mainstay of basal cell carcinoma treatment involves surgical modalities, such as electrodessication and curettage, excision, cryosurgery, and Mohs micrographic surgery. Such methods are typically reserved for localized basal cell carcinoma and offer high five-year cure rates, but come with the risk of functional impairment, disfigurement, and scarring. Here, the authors review the evidence and indications for nonsurgical treatment modalities in cases where surgery is impractical, contraindicated, or simply not desired by the patient. PMID:27386043

  16. Neuron changes in a mollusk in response to proteolytic enzymes.

    PubMed

    Sotnikov, O S; Lukovnikova, M V; Vasyagina, N Yu; Laktionova, A A; Paramonova, N M

    2010-09-01

    The aims of the present work were to investigate the structure of neurons after treatment with proteases and to identify possible recovery of interneuronal syncytial connections. In the first series of experiments, phase-contrast microscopy studies of live dissociated neurons from ganglia of the mollusk Lymnaea stagnalis treated with 0.4% pronase solution demonstrated retraction of nerve processes and biphasic changes in cell body volume. At stage I, at an average of 82.5 min, neuron body volume decreased by 12.1%, after which it increased by a mean of 14.1%. Signs of neuron viability in Ringer's solution were seen for an average of 828 min; survival time in pronase solution was 1.4 times shorter. In the second series of experiments, studies of neuron ultrastructure showed many cases of persistence of mitochondria, the rough and smooth endoplasmic reticulum (ER), Golgi complex, light and granular vesicles, nuclear structure, and neuroplasm optical density. Cells coming close together after centrifugation formed intracellular clefts of uniform width (about 20 nm). There were very rare cases of points at which membranes came into contact. There were no signs of syncytial connections. Lengthening and fusion of smooth ER cisterns separated fragments of neuron bodies from relatively undamaged cells. Some neurons were damaged, with multiple vacuoles formed form swollen mitochondria and ER cisterns. Fragments of nerve processes formed on dissociation were surrounded by a normal outer cell membrane. PMID:20652422

  17. Bivalve mollusks in metal pollution studies: from bioaccumulation to biomonitoring.

    PubMed

    Zuykov, Michael; Pelletier, Emilien; Harper, David A T

    2013-09-01

    Contemporary environmental challenges have emphasized the need to critically assess the use of bivalve mollusks in chemical monitoring (identification and quantification of pollutants) and biomonitoring (estimation of environmental quality). Many authors, however, have considered these approaches within a single context, i.e., as a means of chemical (e.g. metal) monitoring. Bivalves are able to accumulate substantial amounts of metals from ambient water, but evidence for the drastic effects of accumulated metals (e.g. as a TBT-induced shell deformation and imposex) on the health of bivalves has not been documented. Metal bioaccumulation is a key tool in biomonitoring; bioavailability, bioaccumulation, and toxicity of various metals in relation to bivalves are described in some detail including the development of biodynamic metal bioaccumulation model. Measuring metal in the whole-body or the tissue of bivalves themselves does not accurately represent true contamination levels in the environment; these data are critical for our understanding of contaminant trends at sampling sites. Only rarely has metal bioaccumulation been considered in combination with data on metal concentrations in parts of the ecosystem, observation of biomarkers and environmental parameters. Sclerochemistry is in its infancy and cannot be reliably used to provide insights into the pollution history recorded in shells. Alteration processes and mineral crystallization on the inner shell surface are presented here as a perspective tool for environmental studies. PMID:23751124

  18. Oxygen and carbon isotopes in terrestrial mollusk shells. From modern to fossil values, climatic impact on the mollusk diet.

    NASA Astrophysics Data System (ADS)

    Metref, S.; Labonne, M.; Rousseau, D.; Rousseau, D.; Bentaleb, I.; Vianey-Liaud, M.

    2001-12-01

    Stable isotope studies on fossil material as well as on sediment have been very successful these past years indicating such method a very promising Quaternary paleonvironmental index for continental studies. Although most of the studies on fossil material was related to modern material collected near the fossil record, no precise analysis of the impact of the diet and precipitation was carried out in order to justify the previous assumptions. Here we present the results of two sets of analysis from terrestrial mollusk shells, a particularly good climate indicator. On one hand, individuals from hatched eggs of raised Helix aspersa were fed with different plants characteristic of the two main photosynthetic pathways (C3 and C4), and waters of different isotopic values. The shells were analyzed in order to observe the impact of the food diet and of the precipitation on the isotope content of the shell carbonate. On the other hand, the study of fossil shells (Vertigo modesta) from the loess series of the Great Plains, an area where shifts in photosynthetic pathways where detected during the last isotopic stage 2 (24,000-12,000 yr B.P.), is carried out. The interpretation of the results is based on those of the study of modern shells

  19. Genetic considerations for mollusk production in aquaculture: current state of knowledge

    PubMed Central

    Astorga, Marcela P.

    2014-01-01

    In 2012, world mollusk production in aquaculture reached a volume of 15,171,000 tons, representing 23% of total aquaculture production and positioning mollusks as the second most important category of aquaculture products (fishes are the first). Clams and oysters are the mollusk species with the highest production levels, followed in descending order by mussels, scallops, and abalones. In view of the increasing importance attached to genetic information on aquaculture, which can help with good maintenance and thus the sustainability of production, the present work offers a review of the state of knowledge on genetic and genomic information about mollusks produced in aquaculture. The analysis was applied to mollusks which are of importance for aquaculture, with emphasis on the 5 species with the highest production levels. According to FAO, these are: Japanese clam Ruditapes philippinarum; Pacific oyster Crassostrea gigas; Chilean mussel Mytilus chilensis; Blood clam Anadara granosa and Chinese clam Sinonovacula constricta. To date, the genomes of 5 species of mollusks have been sequenced, only one of which, Crassostrea gigas, coincides with the species with the greatest production in aquaculture. Another important species whose genome has been sequenced is Mytilus galloprovincialis, which is the second most important mussel in aquaculture production, after M. chilensis. Few genetic improvement programs have been reported in comparison with the number reported in fish species. The most commonly investigated species are oysters, with at least 5 genetic improvement programs reported, followed by abalones with 2 programs and mussels with one. The results of this work will establish the current situation with respect to the genetics of mollusks which are of importance for aquaculture production, in order to assist future decisions to ensure the sustainability of these resources. PMID:25540651

  20. Life beyond the Basal.

    ERIC Educational Resources Information Center

    Grey, Jeanne; Carbone, Carole

    1987-01-01

    Reading is a tool for learning. The goal for the teaching of reading must be to produce lovers of reading. A holistic approach should replace exclusive dependence on basal readers. Effective methods are the following: (1) language experience approach; (2) word banks; (3) pattern books; (4) sustained silent reading; and (5) directed…

  1. Structural organization of the nervous system of the mantle cavity wall and organs in prosobranch mollusks.

    PubMed

    Zaitseva, O V

    2003-03-01

    A variety of common histological stains was used, along with the Golgi and Colognier silver impregnation methods and electron microscopy, to perform a comparative study of the morphological characteristics of receptor and nerve cells and their interactions in the nervous system of the wall of the mantle cavity and mantle derivatives - gills, siphon, and osphradia - of the marine prosobranch gastropod mollusks Buccinum undatum and Littorina littorea. The results are discussed along with our own previously obtained data on the organization of the osphradial sensory organs and the afferent elements of the mantle cavity wall in other prosobranch mollusks - the terrestrial Pomatia elegans and the freshwater Viviparus contectus and Pomacea paludosa. Using the nervous system of the complex of mantle organs of prosobranch mollusks as examples, the structural features and evolutionary trends of the afferent part of the visceral nervous system of gastropods are discussed. PMID:12762596

  2. Role of bivalve mollusks in the sediment balance of the Anapa Bay Bar

    NASA Astrophysics Data System (ADS)

    Kosyan, A. R.; Kucheruk, N. V.; Flint, M. V.

    2012-02-01

    The sandy beaches of Anapa Bay Bar are a unique natural resource, but they are gradually being degrade under both natural and anthropogenic factors. The emissions of sand and shelly ground from the adjacent sea bottom partly compensate for this process. The concentration of carbonates may reach up to 50% in the beach sands, and most of these carbonates are of mollusk origin. The major deposit formation role belongs to the key bivalve species: Chamelea gallina (Linnaeus, 1758). The average biomass of this mollusk species reaches up to 450 g/m2 at the depths of 5-10 m. The other two subdominating mollusk species, the bivalve Donax trunculus (Linnaeus, 1758) and the gastropod Rapana venosa (Valenciennes, 1846), may impact as 16 g/m2 and 6 g/m2, respectively. Annually, 350 kg of shelly ground per running meter are newly deposited on Anapa beach.

  3. Mollusks from late Mesozoic seep deposits, chiefly in California.

    PubMed

    Kaim, Andrzej; Jenkins, Robert G; Tanabe, Kazushige; Kiel, Steffen

    2014-01-01

    Twenty-nine mollusk species from Late Jurassic to Eocene hydrocarbon seep deposits from California (USA), Japan, New Zealand, and Barbados are described and illustrated. Twenty species belong to Gastropoda and nine to Bivalvia. Seven new species, three new genera, and one new family are introduced. The gastropod Hikidea gen. nov. includes smooth-shelled Cantrainea-like colloniins from Cretaceous hydrocarbon seeps and plesiosaur falls. Hikidea osoensis sp. nov. is the oldest species of this genus. Chilodonta? reticulata sp. nov. is a distinctive vetigastropod though its supraspecific position is unclear. Phanerolepida onoensis sp. nov. is the first species of this colloniin genus from a seep deposit. We describe two new genera of Hokkaidoconchidae: Abyssomelania gen. nov. and Ascheria gen. nov.; this family includes now four genera (including Hokkaidoconcha and Humptulipsia) and ranges from the Late Jurassic to the Eocene. Abyssomelania is characterized by a large, high-spired shell and unusual widely-spaced prosocline riblets (here called abyssomelaniid riblets). Abyssomelania is represented by two new species: A. cramptoni sp. nov. from the Late Cretaceous of New Zealand and A. campbellae sp. nov. from the Early Cretaceous of California. Ascheria gen. nov. is characterized by a large high-spired cerithiform shell, a subsutural constriction, and mostly reticulate ornament. Two nominate species are included: Ascheria gigantea (Kiel et al., 2008) and A. eucosmeta (Ascher, 1906), both of Early Cretaceous age. Two further species potentially belonging to Ascheria from the Eocene of Barbados are reported in open nomenclature and are re-illustrated and re-described for comparison. Humtulipsia nobuharai sp. nov. is described based on specimens from the Campanian-Maastrichtian Sada Limestone seep deposit in Japan. The new family Paskentanidae fam. nov. is introduced for the genera Paskentana and Atresius. The species of this family are characterized by thin-shelled, broad

  4. Acute sensitivity of freshwater mollusks and commonly tested invertebrates to select chemicals with different toxic models of action

    EPA Science Inventory

    Previous studies indicate that freshwater mollusks are more sensitive than commonly tested organisms to some chemicals, such as copper and ammonia. Nevertheless, mollusks are generally under-represented in toxicity databases. Studies are needed to generate data with which to comp...

  5. The calibration of clumped-isotope thermometry on modern marine mollusk

    NASA Astrophysics Data System (ADS)

    Canavan, R. R.; Affek, H. P.; Zaarur, S.; Douglas, P. M.; Wang, Z.

    2013-12-01

    Clumped-isotope (Δ47) thermometry is a novel method to reconstruct paleotemperatures that can be applied to studying past coastal and marine environments using marine mollusk shells. Macrofossil mollusk shells are common in the fossil record and provide enough material to satisfy the relatively large-sample requirement for Δ47 analysis, making them ideal for clumped-isotope paleothermometry. If consistent with the clumped isotope thermometer, mollusk Δ47 derived temperatures should record local water temperatures during shell growth season. Recent studies, however, show strong deviations from the empirical Δ47-T calibration derived from synthetic calcite in some modern mollusk shells (cephalopods, gastropods and bivalves; Dennis et al., 2013; Henkes et al., 2013; Eagle et al., 2013) but not in others (bivalves; Douglas et al., submitted; Came et al., 2007). The source of these discrepancies has been hypothesized to be related to 1) different laboratory techniques (including sample preparation and instrument standardization), 2) growth of CaCO3 polymorphs (calcite, aragonite or vaterite) in shells, and 3) variable environmental growth conditions such as salinity and pH. We test the effect of CaCO3 polymorph, taxonomy, and mollusk growth conditions by comparing among Δ47 values of calcitic shells from eastern oysters (Crassostrea virginica), those of clam shells that are mostly aragonitic (collected along the United States' Atlantic coast), and published calibrations of the clumped isotope thermometer. Atlantic oysters were collected from 37°N to 43°N latitude, with temperatures ranging between ~ 10-25°C, and brackish to marine salinities ranging from 14.5 - 34 PSU. Clam genera were similarly collected along the coast between Florida up north to Maine with growth temperatures ranging from ~ 10-22 °C. We further examine whether the deviation from the calibration is related to the relatively low reproducibility observed in modern mollusk Δ47 measurements, and

  6. Nevoid basal cell carcinoma syndrome

    MedlinePlus

    ... of this disorder is a type of skin cancer called basal cell carcinoma , that develops around the time of puberty. Other ... if: You or any family members have nevoid basal cell carcinoma syndrome, especially if you are planning to have ...

  7. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... consumers to higher trophic levels. The reduction or potential elimination of food chain organism... aquatic organisms in the food web. 230.31 Section 230.31 Protection of Environment ENVIRONMENTAL... § 230.31 Fish, crustaceans, mollusks, and other aquatic organisms in the food web. (a) Aquatic...

  8. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... consumers to higher trophic levels. The reduction or potential elimination of food chain organism... aquatic organisms in the food web. 230.31 Section 230.31 Protection of Environment ENVIRONMENTAL... § 230.31 Fish, crustaceans, mollusks, and other aquatic organisms in the food web. (a) Aquatic...

  9. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... consumers to higher trophic levels. The reduction or potential elimination of food chain organism... aquatic organisms in the food web. 230.31 Section 230.31 Protection of Environment ENVIRONMENTAL... § 230.31 Fish, crustaceans, mollusks, and other aquatic organisms in the food web. (a) Aquatic...

  10. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... consumers to higher trophic levels. The reduction or potential elimination of food chain organism... aquatic organisms in the food web. 230.31 Section 230.31 Protection of Environment ENVIRONMENTAL... § 230.31 Fish, crustaceans, mollusks, and other aquatic organisms in the food web. (a) Aquatic...

  11. 40 CFR 230.31 - Fish, crustaceans, mollusks, and other aquatic organisms in the food web.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Fish, crustaceans, mollusks, and other aquatic organisms in the food web. 230.31 Section 230.31 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b)(1) GUIDELINES FOR SPECIFICATION OF DISPOSAL SITES FOR DREDGED OR FILL MATERIAL...

  12. Effect of the 1982-1983 El Nino on bivalve mollusks. [Chione subrugosa; Trachycardium procerum

    SciTech Connect

    Rollins, H.B.

    1986-01-01

    Mollusks from the peruvian coast were studied in 1984 for shell patterns indicative of stress caused by the 1982-1983 El Nino. Analysis of growth increments showed physiological stress, and there was evidence (from interviews with fishermen) of sever mortality for some species.

  13. Progenesis in the evolution of the nudibranch mollusks genus Dendronotus (Gastropoda: Nudibranchia).

    PubMed

    Ekimova, I A; Malakhov, V V

    2016-03-01

    The morphology and postlarval ontogenesis of the radula in 11 species of the genus Dendronotus Alder et Hancock, 1845, has been studied. Four types of radula are recognized in adult mollusks. Proposed evidence suggests that small species of Dendronotus have evolved by progenesis. PMID:27193883

  14. Venomous mollusks: the risks of human accidents by conus snails (gastropoda: conidae) in Brazil.

    PubMed

    Haddad, Vidal; de Paula Neto, João Batista; Cobo, Válter José

    2006-01-01

    Mollusks of the genus Conus present a venomous apparatus composed of radulae, a chitin structure linked to glands, which injects potent neurotoxic peptides, causing serious human envenomation and even death, associated with the blockage of certain receptors and muscular paralysis. No reported envenomation has occurred in Brazil, but certain populations are at risk of accidents. PMID:17160331

  15. Cortical basal ganglionic degeneration.

    PubMed

    Scarmeas, N; Chin, S S; Marder, K

    2001-10-01

    In this case study, we describe the symptoms, neuropsychological testing, and brain pathology of a retired mason's assistant with cortical basal ganglionic degeneration (CBGD). CBGD is an extremely rare neurodegenerative disease that is categorized under both Parkinsonian syndromes and frontal lobe dementias. It affects men and women nearly equally, and the age of onset is usually in the sixth decade of life. CBGD is characterized by Parkinson's-like motor symptoms and by deficits of movement and cognition, indicating focal brain pathology. Neuronal cell loss is ultimately responsible for the neurological symptoms. PMID:14602941

  16. Trace fossils of precambrian metazoans "Vendobionta" and "Mollusks"

    NASA Astrophysics Data System (ADS)

    Ivantsov, A. Yu.

    2013-05-01

    Metazoan trace fossils from the Upper Vendian are preserved together with remains of corresponding organisms. The traces belong to "Vendobionta", representing the Precambrian phylum Proarticulata and to a presumably trochophoran animal Kimberella quadrata. These organisms fed on microbial mats, which preserved fossil traces. Impressions of the mat surface structures, traces, and bodies of animals are preserved in marine terrigenous sediments on the basal surfaces of sandstone beds. Proarticulata grazing traces are represented by groups and chains of impressions left by the ventral side of a body or its central and posterior parts. Kimberella traces are represented by long ridges united into bundles, fans, and chains of fans. All these traces were largely formed mechanically, i.e., by mat scratching with cilia (Proarticulata) or teeth ( Kimberella). Proarticulata representatives destroyed only a thin upper layer of the mat, while Kimberella could possibly scratch the mat through its entire thickness or even tear off pieces from it.

  17. Paramecium tetraurelia basal body structure.

    PubMed

    Tassin, Anne-Marie; Lemullois, Michel; Aubusson-Fleury, Anne

    2015-01-01

    Paramecium is a free-living unicellular organism, easy to cultivate, featuring ca. 4000 motile cilia emanating from longitudinal rows of basal bodies anchored in the plasma membrane. The basal body circumferential polarity is marked by the asymmetrical organization of its associated appendages. The complex basal body plus its associated rootlets forms the kinetid. Kinetids are precisely oriented within a row in correlation with the cell polarity. Basal bodies also display a proximo-distal polarity with microtubule triplets at their proximal ends, surrounding a permanent cartwheel, and microtubule doublets at the transition zone located between the basal body and the cilium. Basal bodies remain anchored at the cell surface during the whole cell cycle. On the opposite to metazoan, there is no centriolar stage and new basal bodies develop anteriorly and at right angle from the base of the docked ones. Ciliogenesis follows a specific temporal pattern during the cell cycle and both unciliated and ciliated docked basal bodies can be observed in the same cell. The transition zone is particularly well organized with three distinct plates and a maturation of its structure is observed during the growth of the cilium. Transcriptomic and proteomic analyses have been performed in different organisms including Paramecium to understand the ciliogenesis process. The data have incremented a multi-organism database, dedicated to proteins involved in the biogenesis, composition and function of centrosomes, basal bodies or cilia. Thanks to its thousands of basal bodies and the well-known choreography of their duplication during the cell cycle, Paramecium has allowed pioneer studies focusing on the structural and functional processes underlying basal body duplication. Proteins involved in basal body anchoring are sequentially recruited to assemble the transition zone thus indicating that the anchoring process parallels the structural differentiation of the transition zone. This feature

  18. Human basal body basics.

    PubMed

    Vertii, Anastassiia; Hung, Hui-Fang; Hehnly, Heidi; Doxsey, Stephen

    2016-01-01

    In human cells, the basal body (BB) core comprises a ninefold microtubule-triplet cylindrical structure. Distal and subdistal appendages are located at the distal end of BB, where they play indispensable roles in cilium formation and function. Most cells that arrest in the G0 stage of the cell cycle initiate BB docking at the plasma membrane followed by BB-mediated growth of a solitary primary cilium, a structure required for sensing the extracellular environment and cell signaling. In addition to the primary cilium, motile cilia are present in specialized cells, such as sperm and airway epithelium. Mutations that affect BB function result in cilia dysfunction. This can generate syndromic disorders, collectively called ciliopathies, for which there are no effective treatments. In this review, we focus on the features and functions of BBs and centrosomes in Homo sapiens. PMID:26981235

  19. [Microsymbiocenosis of Codiella mollusks as a basis for symbiotic relations in the parasite-host system in opisthorchiasis].

    PubMed

    Kataeva, L V; Karpukhina, N F; Stepanova, K B; Kolotova, O N

    2014-01-01

    The purpose of the first step of microparasitocenosis investigation was to study the microbiocenosis of the first intermediate hosts of O. felineus--prosobranch gastropods of the genus Codiella, as well as their habitats. Materials were collected in the Iryum River of the Ob-Irtysh basin. The microflora of mollusks, water, and soil from their habitats was examined. The predominant flora was Aeromonas species in the biocenosis of mollusks and Enterobacteriaceae in the microbiocenosis of the water basin and soil. Examination of the microbial communities in the mollusks and their habitats showed that the range of microbial populations of mollusks was wider in species composition as compared to the microbiocenosis of soil and water. PMID:25286543

  20. Development of electric environment to control mollusk-shaped gel robots made of electroactive polymer PAMPS gel

    NASA Astrophysics Data System (ADS)

    Otake, Mihoko; Inaba, Masayuki; Inoue, Hirochika

    2000-06-01

    This paper describes the design and implementation of electric fields to actuate mollusk-shaped robots made entirely of PAMPS gel, which is a kind of electro-active polymer (EAP). The purpose of this study is to develop a system to control the shape of both simulated and real gel robots using electric fields. We present a modeling framework and experimental results using a prototype mollusk-shaped EAP robot that locomotes by changing the shape of its whole body.

  1. Parasitizing of trematodes provokes warts on the hinge plate of the bivalve mollusk Macoma balthica Linnaeus, 1758 (Veneroida, Tellinidae).

    PubMed

    Gantsevich, M M; Strelkov, P P; Basova, L A; Malakhov, V V

    2016-01-01

    The hypothesis on non-random correlation between abnormalities in the structure of hinge plate and infection of mollusks Macoma balthica with trematodes of the family Gymnophallidae has been tested on the basis of material from the Barents Sea. Significant correlation between the presence of warts and infection was established upon intraand interpopulation comparison. The hypothesis states that parasitizing of trematodes in the extrapallial cavity of mollusks influences the mantle functioning and provokes abnormalities in the hinge plate structure. PMID:27021361

  2. Cationic surfactants for control of fresh- and saltwater mollusks in nuclear cooling systems

    SciTech Connect

    Post, R.M.; Mallen, E.; Lehmann, F.

    1991-11-01

    One result of the release of the US Nuclear Regulatory Commission's Generic Letter 89-13, Service Water Problems Affecting Safety-Related Equipment, was the heightened awareness of the nuclear industry to the problems of macrofouling in heat exchange systems. The principal mollusk species that contribute to freshwater macrofouling problems are Asiatic Clam (southern United States) and Zebra Mussel (Great Lakes). The predominant saltwater fouling mollusks are the Blue Mussel (Pacific, northern Atlantic), Ribbed Mussel (southern Atlantic, Gulf Coast), and American Oyster (Atlantic, Gulf Coast). The nuclear community's awareness of macrofouling problems and the ineffectiveness of intermittent chlorination programs have led to the development of several chemical control technologies for eliminating macrofouling organism infestation. One technology that has proven effective for the control of macrofouling organisms is the periodic addition of a combination of two cationic charged surfactants, specifically, alkyldimethylbenzylammonium chloride (QUAT) and dodecyl guanidine hydrochloride (DGH). Experience with the cationic surfactants at several nuclear power plants is reported.

  3. Biosorption of divalent Pb, Cd and Zn on aragonite and calcite mollusk shells.

    PubMed

    Du, Yang; Lian, Fei; Zhu, Lingyan

    2011-07-01

    The potential of using mollusk shell powder in aragonite (razor clam shells, RCS) and calcite phase (oyster shells, OS) to remove Pb(2+), Cd(2+) and Zn(2+) from contaminated water was investigated. Both biogenic sorbents displayed very high sorption capacities for the three metals except for Cd on OS. XRD, SEM and XPS results demonstrated that surface precipitation leading to crystal growth took place during sorption. Calcite OS displayed a remarkably higher sorption capacity to Pb than aragonite RCS, while the opposite was observed for Cd. However, both sorbents displayed similar sorption capacities to Zn. These could be due to the different extent of matching in crystal lattice between the metal bearing precipitate and the substrates. The initial pH of the solution, sorbent's dosage and grain size affected the removal efficiency of the heavy meals significantly, while the organic matter in mollusk shells affected the removal efficiency to a lesser extent. PMID:21550150

  4. Environmental heterogeneity predicts species richness of freshwater mollusks in sub-Saharan Africa

    NASA Astrophysics Data System (ADS)

    Hauffe, T.; Schultheiß, R.; Van Bocxlaer, B.; Prömmel, K.; Albrecht, C.

    2014-12-01

    Species diversity and how it is structured on a continental scale is influenced by stochastic, ecological, and evolutionary driving forces, but hypotheses on determining factors have been mainly examined for terrestrial and marine organisms. The extant diversity of African freshwater mollusks is in general well assessed to facilitate conservation strategies and because of the medical importance of several taxa as intermediate hosts for tropical parasites. This historical accumulation of knowledge has, however, not resulted in substantial macroecological studies on the spatial distribution of freshwater mollusks. Here, we use continental distribution data and a recently developed method of random and cohesive allocation of species distribution ranges to test the relative importance of various factors in shaping species richness of Bivalvia and Gastropoda. We show that the mid-domain effect, that is, a hump-shaped richness gradient in a geographically bounded system despite the absence of environmental gradients, plays a minor role in determining species richness of freshwater mollusks in sub-Saharan Africa. The western branch of the East African Rift System was included as dispersal barrier in richness models, but these simulation results did not fit observed diversity patterns significantly better than models where this effect was not included, which suggests that the rift has played a more complex role in generating diversity patterns. Present-day precipitation and temperature explain richness patterns better than Eemian climatic condition. Therefore, the availability of water and energy for primary productivity during the past does not influence current species richness patterns much, and observed diversity patterns appear to be in equilibrium with contemporary climate. The availability of surface waters was the best predictor of bivalve and gastropod richness. Our data indicate that habitat diversity causes the observed species-area relationship, and hence, that

  5. Comparative uptake from sea water and tissue distribution of 60Co in marine mollusks

    SciTech Connect

    Carvalho, F.P.

    1987-07-01

    Five different species of marine mollusks, Mytilus galloprovincialis Lmk., Tapes decussatus L., Cerastoderma (Cardium) edule (L.), Donax vittatus (da Costa) and Patella vulgata L., were exposed to /sup 60/Co-labelled sea water under laboratory conditions. After a 1-mo exposure, tested species reached different whole-body /sup 60/Co concentration factors (CF) over radioactive sea water of 73 +/- 27, 22 +/- 10, 84 +/- 25, 6.3 +/- 1.4 and 31 +/- 10, respectively, which are not dependent upon the size of mollusks. Equations for the experimental uptake curves, obtained using a multi-exponential model, indicate that /sup 60/Co uptake by mollusks involves two or three compartments, according to the species. In all species, the larger compartments turn over with long biological half-lives, dependent upon species. At the beginning of the experiment, /sup 60/CoCl2 added to sea water was mainly in cationic forms. These forms were progressively converted into anionic plus neutral forms most likely due to complex formation with organic ligands. With time this physico-chemical evolution had a lowering effect on /sup 60/Co bioaccumulation by mollusks. Analysis of /sup 60/Co in tissues revealed that Donax shell and mantle do not accumulate the radionuclide in great quantities, generating the low whole-body concentration factor found. In contrast, shell and mantle from all other species displayed variable but high CFs. Shell by itself accounts for more than half of the /sup 60/Co whole-body burden. Among soft tissues, gills and viscera displayed the highest CF and muscle the lowest. From these experiments, one may conclude that significant differences among species do exist regarding Co bioaccumulation potential.

  6. Nature's Palette: Characterization of Shared Pigments in Colorful Avian and Mollusk Shells.

    PubMed

    Verdes, Aida; Cho, Wooyoung; Hossain, Marouf; Brennan, Patricia L R; Hanley, Daniel; Grim, Tomáš; Hauber, Mark E; Holford, Mandë

    2015-01-01

    Pigment-based coloration is a common trait found in a variety of organisms across the tree of life. For example, calcareous avian eggs are natural structures that vary greatly in color, yet just a handful of tetrapyrrole pigment compounds are responsible for generating this myriad of colors. To fully understand the diversity and constraints shaping nature's palette, it is imperative to characterize the similarities and differences in the types of compounds involved in color production across diverse lineages. Pigment composition was investigated in eggshells of eleven paleognath bird taxa, covering several extinct and extant lineages, and shells of four extant species of mollusks. Birds and mollusks are two distantly related, calcareous shell-building groups, thus characterization of pigments in their calcareous structures would provide insights to whether similar compounds are found in different phyla (Chordata and Mollusca). An ethylenediaminetetraacetic acid (EDTA) extraction protocol was used to analyze the presence and concentration of biliverdin and protoporphyrin, two known and ubiquitous tetrapyrrole avian eggshell pigments, in all avian and molluscan samples. Biliverdin was solely detected in birds, including the colorful eggshells of four tinamou species. In contrast, protoporphyrin was detected in both the eggshells of several avian species and in the shells of all mollusks. These findings support previous hypotheses about the ubiquitous deposition of tetrapyrroles in the eggshells of various bird lineages and provide evidence for its presence also across distantly related animal taxa. PMID:26650398

  7. Bacillary Necrosis, a Disease of Larval and Juvenile Bivalve Mollusks I. Etiology and Epizootiology

    PubMed Central

    Tubiash, Haskell S.; Chanley, Paul E.; Leifson, Einar

    1965-01-01

    Tubiash, Haskell S. (U.S. Bureau of Commercial Fisheries, Milford, Conn.), Paul E. Chanley, and Einar Leifson. Bacillary necrosis, a disease of larval and juvenile bivalve mollusks. I. Etiology and epizootiology. J. Bacteriol. 90:1036–1044. 1965.—Lethal bacterial infections of a variety of hatchery-spawned bivalve mollusk larvae and juveniles have been studied. The symptoms of the disease and the course of the infection are described. Four biotypes and five antigenic types of bacteria, pathogenic for the larvae of five species of bivalve mollusks, were isolated and described in some detail. All are gram-negative motile rods. Comparative studies were made of a fairly large number of similar bacteria isolated from presumably normal marine fauna. None of these was pathogenic for the bivalve larvae nor did they have antigens in common with the pathogenic group. The four biotypes had a number of characteristics in common that rarely were present in other cultures from marine fauna. Several antibiotic preparations proved to be of value in the treatment and control of the infection. Images PMID:5847794

  8. Nature’s Palette: Characterization of Shared Pigments in Colorful Avian and Mollusk Shells

    PubMed Central

    Brennan, Patricia L. R.; Hanley, Daniel; Grim, Tomáš; Hauber, Mark E.; Holford, Mandë

    2015-01-01

    Pigment-based coloration is a common trait found in a variety of organisms across the tree of life. For example, calcareous avian eggs are natural structures that vary greatly in color, yet just a handful of tetrapyrrole pigment compounds are responsible for generating this myriad of colors. To fully understand the diversity and constraints shaping nature’s palette, it is imperative to characterize the similarities and differences in the types of compounds involved in color production across diverse lineages. Pigment composition was investigated in eggshells of eleven paleognath bird taxa, covering several extinct and extant lineages, and shells of four extant species of mollusks. Birds and mollusks are two distantly related, calcareous shell-building groups, thus characterization of pigments in their calcareous structures would provide insights to whether similar compounds are found in different phyla (Chordata and Mollusca). An ethylenediaminetetraacetic acid (EDTA) extraction protocol was used to analyze the presence and concentration of biliverdin and protoporphyrin, two known and ubiquitous tetrapyrrole avian eggshell pigments, in all avian and molluscan samples. Biliverdin was solely detected in birds, including the colorful eggshells of four tinamou species. In contrast, protoporphyrin was detected in both the eggshells of several avian species and in the shells of all mollusks. These findings support previous hypotheses about the ubiquitous deposition of tetrapyrroles in the eggshells of various bird lineages and provide evidence for its presence also across distantly related animal taxa. PMID:26650398

  9. Mercury accumulation in hydrothermal vent mollusks from the southern Tonga Arc, southwestern Pacific Ocean.

    PubMed

    Lee, Seyong; Kim, Se-Joo; Ju, Se-Jong; Pak, Sang-Joon; Son, Seung-Kyu; Yang, Jisook; Han, Seunghee

    2015-05-01

    We provide the mercury (Hg) and monomethylmercury (MMHg) levels of the plume water, sulfide ore, sediment, and mollusks located at the hydrothermal vent fields of the southern Tonga Arc, where active volcanism and intense seismic activity occur frequently. Our objectives were: (1) to address the potential release of Hg from hydrothermal fluids and (2) to examine the distribution of Hg and MMHg levels in hydrothermal mollusks (mussels and snails) harboring chemotrophic bacteria. While high concentrations of Hg in the sediment and Hg, As, and Sb in the sulfide ore indicates that their source is likely hydrothermal fluids, the MMHg concentration in the sediment was orders of magnitude lower than the Hg (<0.001%). It suggests that Hg methylation may have not been favorable in the vent field sediment. In addition, Hg concentrations in the mollusks were much higher (10-100 times) than in other hydrothermal vent environments, indicating that organisms located at the Tonga Arc are exposed to exceedingly high Hg levels. While Hg concentration was higher in the gills and digestive glands than in the mantles and residues of snails and mussels, the MMHg concentrations in the gills and digestive glands were orders of magnitude lower (0.004-0.04%) than Hg concentrations. In summary, our results suggest that the release of Hg from the hydrothermal vent fields of the Tonga Arc and subsequent bioaccumulation are substantial, but not for MMHg. PMID:25748345

  10. Lipids and Fatty Acids of Nudibranch Mollusks: Potential Sources of Bioactive Compounds

    PubMed Central

    Zhukova, Natalia V.

    2014-01-01

    The molecular diversity of chemical compounds found in marine animals offers a good chance for the discovery of novel bioactive compounds of unique structures and diverse biological activities. Nudibranch mollusks, which are not protected by a shell and produce chemicals for various ecological uses, including defense against predators, have attracted great interest for their lipid composition. Lipid analysis of eight nudibranch species revealed dominant phospholipids, sterols and monoalkyldiacylglycerols. Among polar lipids, 1-alkenyl-2-acyl glycerophospholipids (plasmalogens) and ceramide-aminoethyl phosphonates were found in the mollusks. The fatty acid compositions of the nudibranchs differed greatly from those of other marine gastropods and exhibited a wide diversity: very long chain fatty acids known as demospongic acids, a series of non-methylene-interrupted fatty acids, including unusual 21:2∆7,13, and an abundance of various odd and branched fatty acids typical of bacteria. Symbiotic bacteria revealed in some species of nudibranchs participate presumably in the production of some compounds serving as a chemical defense for the mollusks. The unique fatty acid composition of the nudibranchs is determined by food supply, inherent biosynthetic activities and intracellular symbiotic microorganisms. The potential of nudibranchs as a source of biologically active lipids and fatty acids is also discussed. PMID:25196731

  11. Soft-shell clam, Mya arenaria, a convenient laboratory animal for screening pathogens of bivalve mollusks.

    PubMed

    Tubiash, H S

    1971-09-01

    Attempts to introduce infectious or foreign material into oysters and other bivalve mollusks usually involve force or trauma because of immediate, prolonged adduction of the tightly closing valves. The soft-shell clam, Mya arenaria, is unable to seal its valves completely and relaxes readily, exposing soft tissue and a large siphon. This species is free from fouling organisms and is readily available at all seasons in the New England and mid-Atlantic areas. Suspensions of five strains of Vibrio sp. that cause bacillary necrosis in larval and juvenile bivalve mollusks were injected into the heart, siphon tissue, and the incurrent and excurrent siphon lumina of soft-shell clams. All vibrio strains caused significant mortality, usually within 2 days. Heaviest losses resulted from heart and excurrent siphon injections. No mortality occurred in control clams injected with seawater, broth, Serratia sp., and Escherichia coli. The soft-shell clam appears to be a useful animal for testing the pathogenicity of marine microorganisms for bivalve mollusks. PMID:4940871

  12. The curse of physiology—challenges and opportunities in the interpretation of geochemical data from mollusk shells

    NASA Astrophysics Data System (ADS)

    Schöne, Bernd R.

    2008-10-01

    Physiology corrupts geochemical records of mollusk shells in many ways, e.g., by actively controlling the incorporation of trace elements in the skeleton. However, the effects of variable biomineralization rates and growth cessation have largely remained unconsidered. Mediated by endogenous timekeeping mechanisms, mollusks stop growing skeletal material on a regular basis ranging from ultradian to annual timescales. During growth cessation, the shells do not record environmental conditions. Shell growth also stops when environmental conditions are beyond the physiological tolerance of the organism, e.g., above and below genetically determined, species-specific thermal extremes where shell growth slows and eventually ceases. Such growth disruptions can occur at non-periodic time intervals. Due to growth retardations and halts, proxy records of mollusk shells are thus incomplete, and reconstructed environmental amplitudes prone to truncation. Furthermore, environmental records are biased toward the physiological optimum of the animal. Favorable environmental conditions increase shell growth, whereas adverse environmental conditions result in reduced shell production and lowered overall metabolism. Not least, the duration of the growing season and overall growth rate decrease as the mollusk grows older. Mathematical modeling approaches can significantly improve proxy records obtained from mollusk shells. For example, if the duration of growth cessation is known, it may be possible to model the missing environmental record. It is also fairly easy to account for age-related growth trends, or variable time-averaging in different portions of the shell. However, a major premise for a reliable interpretation of proxy records from a mollusk shell or other organisms secreting biogenic hard parts is a proper understanding of the physiology, and of course, a high-resolution record of the many different environmental factors that may influence physiology and shell growth. The

  13. The Nervous Systems of Basally Branching Nemertea (Palaeonemertea)

    PubMed Central

    Beckers, Patrick; Loesel, Rudi; Bartolomaeus, Thomas

    2013-01-01

    In recent years, a lot of studies have been published dealing with the anatomy of the nervous system in different spiralian species. The only nemertean species investigated in this context probably shows derived characters and thus the conditions found there are not useful in inferring the relationship between nemerteans and other spiralian taxa. Ingroup relationships within Nemertea are still unclear, but there is some agreement that the palaeonemerteans form a basal, paraphyletic grade. Thus, palaeonemertean species are likely the most informative when comparing with other invertebrate groups. We therefore analyzed the nervous system of several palaeonemertean species by combining histology and immunostaining. 3D reconstructions based on the aligned slices were performed to get an overall impression of the central nervous system, and immunohistochemistry was chosen to reveal fine structures and to be able to compare the data with recently published results. The insights presented here permit a first attempt to reconstruct the primary organization of the nemertean nervous system. This comparative analysis allows substantiating homology hypotheses for nerves of the peripheral nervous system. This study also provides evidence that the nemertean brain primarily consists of two lobes connected by a strong ventral commissure and one to several dorsal commissures. During nemertean evolution, the brain underwent continuous compartmentalization into a pair of dorsal and ventral lobes interconnected by commissures and lateral tracts. Given that this conclusion can be corroborated by cladistic analyses, nemerteans should share a common ancestor with spiralians that primarily have a simple brain consisting of paired medullary, frontally commissurized and reinforced cords. Such an organization resembles the situation found in presumably basally branching annelids or mollusks. PMID:23785478

  14. The nervous systems of basally branching nemertea (palaeonemertea).

    PubMed

    Beckers, Patrick; Loesel, Rudi; Bartolomaeus, Thomas

    2013-01-01

    In recent years, a lot of studies have been published dealing with the anatomy of the nervous system in different spiralian species. The only nemertean species investigated in this context probably shows derived characters and thus the conditions found there are not useful in inferring the relationship between nemerteans and other spiralian taxa. Ingroup relationships within Nemertea are still unclear, but there is some agreement that the palaeonemerteans form a basal, paraphyletic grade. Thus, palaeonemertean species are likely the most informative when comparing with other invertebrate groups. We therefore analyzed the nervous system of several palaeonemertean species by combining histology and immunostaining. 3D reconstructions based on the aligned slices were performed to get an overall impression of the central nervous system, and immunohistochemistry was chosen to reveal fine structures and to be able to compare the data with recently published results. The insights presented here permit a first attempt to reconstruct the primary organization of the nemertean nervous system. This comparative analysis allows substantiating homology hypotheses for nerves of the peripheral nervous system. This study also provides evidence that the nemertean brain primarily consists of two lobes connected by a strong ventral commissure and one to several dorsal commissures. During nemertean evolution, the brain underwent continuous compartmentalization into a pair of dorsal and ventral lobes interconnected by commissures and lateral tracts. Given that this conclusion can be corroborated by cladistic analyses, nemerteans should share a common ancestor with spiralians that primarily have a simple brain consisting of paired medullary, frontally commissurized and reinforced cords. Such an organization resembles the situation found in presumably basally branching annelids or mollusks. PMID:23785478

  15. [Basal and spinous cell epitheliomas].

    PubMed

    Shaw, M; Sanguinetti, O; de Kaminsky, A R; Kaminsky, C A

    1975-01-01

    A study on 502 epithelial cutaneous cancers was carried out by the authors. The study included 377 basal cell carcinomas (57,5% in males and 42,4% in females) and 125 squamous cell carcinomas (78,4% in males and 21,6% in females). The basal cell carcinomas in both sexs had an earlier onset than the squamous cell carcinomas. PMID:1241706

  16. [Anti-basal ganglia antibody].

    PubMed

    Hayashi, Masaharu

    2013-04-01

    Sydenham's chorea (SC) is a major manifestation of rheumatic fever, and the production of anti-basal ganglia antibodies (ABGA) has been proposed in SC. The pathogenesis is hypothesized as autoimmune targeting of the basal ganglia via molecular mimicry, triggered by streptococcal infection. The spectrum of diseases in which ABGA may be involved has been broadened to include other extrapyramidal movement disorders, such as tics, dystonia, and Parkinsonism, as well as other psychiatric disorders. The autoimmune hypothesis in the presence and absence of ABGA has been suggested in Tourette's syndrome (TS), early onset obsessive-compulsive disorders (OCD), and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). Recently, the relationship between ABGA and dopamine neurons in the basal ganglia has been examined, and autoantibodies against dopamine receptors were detected in the sera from patients with basal ganglia encephalitis. In Japan, the occurrence of subacute encephalitis, where patients suffer from episodes of altered behavior and involuntary movements, has increased. Immune-modulating treatments are effective, indicating the involvement of an autoimmune mechanism. We aimed to detect the anti-neuronal autoantibodies in such encephalitis, using immunohistochemical assessment of patient sera. The sera from patients showing involuntary movements had immunoreactivity for basal ganglia neurons. Further epitopes for ABGA will be investigated in basal ganglia disorders other than SC, TS, OCD, and PANDAS. PMID:23568985

  17. Phylogenetic support values are not necessarily informative: the case of the Serialia hypothesis (a mollusk phylogeny)

    PubMed Central

    Wägele, J Wolfgang; Letsch, Harald; Klussmann-Kolb, Annette; Mayer, Christoph; Misof, Bernhard; Wägele, Heike

    2009-01-01

    Background Molecular phylogenies are being published increasingly and many biologists rely on the most recent topologies. However, different phylogenetic trees often contain conflicting results and contradict significant background data. Not knowing how reliable traditional knowledge is, a crucial question concerns the quality of newly produced molecular data. The information content of DNA alignments is rarely discussed, as quality statements are mostly restricted to the statistical support of clades. Here we present a case study of a recently published mollusk phylogeny that contains surprising groupings, based on five genes and 108 species, and we apply new or rarely used tools for the analysis of the information content of alignments and for the filtering of noise (masking of random-like alignment regions, split decomposition, phylogenetic networks, quartet mapping). Results The data are very fragmentary and contain contaminations. We show that that signal-like patterns in the data set are conflicting and partly not distinct and that the reported strong support for a "rather surprising result" (monoplacophorans and chitons form a monophylum Serialia) does not exist at the level of primary homologies. Split-decomposition, quartet mapping and neighbornet analyses reveal conflicting nucleotide patterns and lack of distinct phylogenetic signal for the deeper phylogeny of mollusks. Conclusion Even though currently a majority of molecular phylogenies are being justified with reference to the 'statistical' support of clades in tree topologies, this confidence seems to be unfounded. Contradictions between phylogenies based on different analyses are already a strong indication of unnoticed pitfalls. The use of tree-independent tools for exploratory analyses of data quality is highly recommended. Concerning the new mollusk phylogeny more convincing evidence is needed. PMID:19555513

  18. A mollusk retinoic acid receptor (RAR) ortholog sheds light on the evolution of ligand binding.

    PubMed

    Gutierrez-Mazariegos, Juliana; Nadendla, Eswar Kumar; Lima, Daniela; Pierzchalski, Keely; Jones, Jace W; Kane, Maureen; Nishikawa, Jun-Ichi; Hiromori, Youhei; Nakanishi, Tsuyoshi; Santos, Miguel M; Castro, L Filipe C; Bourguet, William; Schubert, Michael; Laudet, Vincent

    2014-11-01

    Nuclear receptors are transcription factors that regulate networks of target genes in response to small molecules. There is a strong bias in our knowledge of these receptors because they were mainly characterized in classical model organisms, mostly vertebrates. Therefore, the evolutionary origins of specific ligand-receptor couples still remain elusive. Here we present the identification and characterization of a retinoic acid receptor (RAR) from the mollusk Nucella lapillus (NlRAR). We show that this receptor specifically binds to DNA response elements organized in direct repeats as a heterodimer with retinoid X receptor. Surprisingly, we also find that NlRAR does not bind all-trans retinoic acid or any other retinoid we tested. Furthermore, NlRAR is unable to activate the transcription of reporter genes in response to stimulation by retinoids and to recruit coactivators in the presence of these compounds. Three-dimensional modeling of the ligand-binding domain of NlRAR reveals an overall structure that is similar to vertebrate RARs. However, in the ligand-binding pocket (LBP) of the mollusk receptor, the alteration of several residues interacting with the ligand has apparently led to an overall decrease in the strength of the interaction with the ligand. Accordingly, mutations of NlRAR at key positions within the LBP generate receptors that are responsive to retinoids. Altogether our data suggest that, in mollusks, RAR has lost its affinity for all-trans retinoic acid, highlighting the evolutionary plasticity of its LBP. When put in an evolutionary context, our results reveal new structural and functional features of nuclear receptors validated by millions of years of evolution that were impossible to reveal in model organisms. PMID:25116705

  19. A Mollusk Retinoic Acid Receptor (RAR) Ortholog Sheds Light on the Evolution of Ligand Binding

    PubMed Central

    Gutierrez-Mazariegos, Juliana; Nadendla, Eswar Kumar; Lima, Daniela; Pierzchalski, Keely; Jones, Jace W.; Kane, Maureen; Nishikawa, Jun-Ichi; Hiromori, Youhei; Nakanishi, Tsuyoshi; Santos, Miguel M.; Castro, L. Filipe C.; Bourguet, William

    2014-01-01

    Nuclear receptors are transcription factors that regulate networks of target genes in response to small molecules. There is a strong bias in our knowledge of these receptors because they were mainly characterized in classical model organisms, mostly vertebrates. Therefore, the evolutionary origins of specific ligand-receptor couples still remain elusive. Here we present the identification and characterization of a retinoic acid receptor (RAR) from the mollusk Nucella lapillus (NlRAR). We show that this receptor specifically binds to DNA response elements organized in direct repeats as a heterodimer with retinoid X receptor. Surprisingly, we also find that NlRAR does not bind all-trans retinoic acid or any other retinoid we tested. Furthermore, NlRAR is unable to activate the transcription of reporter genes in response to stimulation by retinoids and to recruit coactivators in the presence of these compounds. Three-dimensional modeling of the ligand-binding domain of NlRAR reveals an overall structure that is similar to vertebrate RARs. However, in the ligand-binding pocket (LBP) of the mollusk receptor, the alteration of several residues interacting with the ligand has apparently led to an overall decrease in the strength of the interaction with the ligand. Accordingly, mutations of NlRAR at key positions within the LBP generate receptors that are responsive to retinoids. Altogether our data suggest that, in mollusks, RAR has lost its affinity for all-trans retinoic acid, highlighting the evolutionary plasticity of its LBP. When put in an evolutionary context, our results reveal new structural and functional features of nuclear receptors validated by millions of years of evolution that were impossible to reveal in model organisms. PMID:25116705

  20. Hydrogen peroxide induces spawning in mollusks, with activation of prostaglandin endoperoxide synthetase.

    PubMed

    Morse, D E; Duncan, H; Hooker, N; Morse, A

    1977-04-15

    Addition of hydrogen peroxide to seawater causes synchronous spawning in gravid male and female abalones, and certain other mollusks as well. This effect is blocked by exposure of the animals to aspirin, an inhibitor of the enzyme catalyzing oxidative synthesis of prostaglandin endoperoxide. Hydrogen peroxide activates this enzymatic reaction in cell-free extracts prepared from abalone eggs (a very rich source of the prostaglandin endoperoxide synthetase); this effect appears to reveal a fundamental property of prostaglandin endoperoxide synthesis. Applicability of these findings to both mariculture and medical purposes is suggested. PMID:403609

  1. Evaluation of tropical water sources and mollusks in southern Brazil using microbiological, biochemical, and chemical parameters.

    PubMed

    Souza, Doris Sobral Marques; Ramos, Ana Paula Dores; Nunes, Fabrício Flores; Moresco, Vanessa; Taniguchi, Satie; Leal, Diego Averaldo Guiguet; Sasaki, Silvio Tarou; Bícego, Márcia Caruso; Montone, Rosalinda Carmela; Durigan, Maurício; Teixeira, Adriano Luiz; Pilotto, Mariana Rangel; Delfino, Nicésio; Franco, Regina Maura Bueno; Melo, Cláudio Manoel Rodrigues de; Bainy, Afonso Celso Dias; Barardi, Célia Regina Monte

    2012-02-01

    Florianópolis, a city located in the Santa Catarina State in southern Brazil, is the national leading producer of bivalve mollusks. The quality of bivalve mollusks is closely related to the sanitary conditions of surrounding waters where they are cultivated. Presently, cultivation areas receive large amounts of effluents derived mainly from treated and non-treated domestic, rural, and urban sewage. This contributes to the contamination of mollusks with trace metals, pesticides, other organic compounds, and human pathogens such as viruses, bacteria, and protozoan. The aim of this study was to perform a thorough diagnosis of the shellfish growing areas in Florianópolis, on the coast of Santa Catarina. The contamination levels of seawater, sediments, and oysters were evaluated for their microbiological, biochemical, and chemical parameters at five sea sites in Florianópolis, namely three regular oyster cultivation areas (Sites 1, 2, and oyster supplier), a polluted site (Site 3), and a heavily polluted site (Site 4). Samples were evaluated at day zero and after 14 days. Seawater and sediment samples were collected just once, at the end of the experiment. Antioxidant defenses, which may occur in contaminated environments in response to the increased production of reactive oxygen species (ROS) by organisms, were analyzed in oysters, as well as organic compounds (in oysters and sediment samples) and microbiological contamination (in oysters and seawater samples). The results showed the presence of the following contaminants: fecal coliforms in seawater samples (four sites), human adenovirus (all sites), human noroviruses GI and GII (two sites), Hepatitis A viruses (one site), JC Polyomavirus in an oyster sample from the oyster supplier, Giardia duodenalis cysts, and Cryptosporidium sp oocysts (one site). Among organochlorine pesticides, only DDT (dichlorodiphenyltrichloroethane) and HCH (hexachlorocyclohexane) were detected in some sediment and oysters samples in very

  2. [Nutrition and biological value of food parts of a trade bivalve mollusk Anadara broughtoni].

    PubMed

    Tabakaeva, O V; Tabakaev, A V

    2015-01-01

    Currently, the human diet includes different new products of seafishing, including non-fish--bivalves and gastropods, holothurias, echinoderms, jellyfishes that demands careful studying of their chemical composition. The purpose of the study was to determine the nutritional and biological value of all soft parts of the burrowing bivalve MOLLUSK Anadara broughtoni from the Far East region. It was established thatfood parts of a bivalve were significantly flooded (water content--73.5-84.2%), with the minimum water content in the adductor and maximum in the mantle. Dry solids are presented by organic (89-93%) and mineral (7-11%) components. Organic components consist of protein (14.6-20.7%), lipids (1.8-2.3%), carbohydrates (2.1-2.6%). The analysis of amino-acid composition of proteins of food parts of the mollusk of Anadara broughtonishowed the presence of all essential amino acids with slight differences in their content depending on the localization of the protein. All edible parts have tryptophan as the limiting amino acid. Muscle proteins have maximum level of lysine, methionine, cysteine, phenylalanine and tyrosine; mantle proteins--leucine, isoleucine and threonine; adductor proteins--valine, phenylalanine, tyrosine, methionine and cysteine. Predominant nonessential amino acids forproteins of all food pieces are glycine, aspartic acid, glutamic acid, arginine. The coefficient of amino-acid score differences of adductor protein (31.7%) is less than the same of cloak by 3.7%. The indicator "biological value" is maximal for adductor (68.3%), but the differenceformuscle is only 0.83%. Mantle proteins are characterized by minimum biological value (64.6%). The coefficient of utility of amino acid composition of protein is maximalfor muscle (57.83%), and values for a cloak and an adductor differ slightly (55.81 and 55.96%). Taurine content in food parts of a mollusk Anadara broughtoni is rather high compared to with other bivalve mollusks of the Far East region

  3. [Risk-benefit of some mollusks and processed fishes in the renal patient's diet].

    PubMed

    Castro-González, M I; Miranda-Becerra, D; Pérez-Gil, R F

    2010-03-01

    The renal diet must include limited amounts of high quality protein, phosphorus P and potassium K. n-3 polyunsaturated fatty acids (n-3PUFA EPA and DHA), present in fishes and mollusks, render beneficial properties against progression of renal damage. The aim of this study was to evaluate protein PR, phosphorus P, potassium K, calcium Ca and n-3PUFA in processed fishes and mollusks as an alimentary option for renal patients. Canned tuna (water AA and oil AC), sardine in tomate sauce ST and chipotle SC and smoked salmon SA, fresh jumbo flying squid CA, common octopus PU and oyster OS were evaluated. Significant difference was detected (p <.0.05) for K between different types of fish. SA contained 38g/100g PR, 307 mg/100g of P, 371 mg/ 100g K and 106 mg/100g n-3PUFA. Sardines contained (279-304 mg/100g of P and 283-322 mg/100g K and tunas 142-160 mg/100g P and 141-154 mg/100g K. Tunas and sardines had elevated concentration of n-3PUFA (4114 and 4790 mg/ 100g respectively), P:n-3PUFA and K:n-3PUFA ratio was low in tunas (0.03) and sardines (0.06). AA and AC contained (10.1 and 11.1 mgP/gPR), while ST and SC provided 26.4-19.1 mg/P/gPR. n-3PUFA/gPR were similar for tunas and sardines (302-424mg/gPR). Mollusks: CA presented the highest values of P and PR (2.4 mg/100g and 18.4g/100g). n-3PUFA ranged from 4.3 to 79 mg/100g in PU and OS respectively. Among processed fishes, only canned tunas are recommended for the diet of renal patients, in an individualized basis. The risk-benefit ratio of sardines in the renal diet should be evaluated, due to their high content of P and n-3PUFA. Salmon and mollusks are not recommended for the renal diet. PMID:21090278

  4. Cardiovascular effects of basal insulins.

    PubMed

    Mannucci, Edoardo; Giannini, Stefano; Dicembrini, Ilaria

    2015-01-01

    Basal insulin is an important component of treatment for both type 1 and type 2 diabetes. One of the principal aims of treatment in patients with diabetes is the prevention of diabetic complications, including cardiovascular disease. There is some evidence, although controversial, that attainment of good glycemic control reduces long-term cardiovascular risk in both type 1 and type 2 diabetes. The aim of this review is to provide an overview of the potential cardiovascular safety of the different available preparations of basal insulin. Current basal insulin (neutral protamine Hagedorn [NPH], or isophane) and basal insulin analogs (glargine, detemir, and the more recent degludec) differ essentially by various measures of pharmacokinetic and pharmacodynamic effects in the bloodstream, presence and persistence of peak action, and within-subject variability in the glucose-lowering response. The currently available data show that basal insulin analogs have a lower risk of hypoglycemia than NPH human insulin, in both type 1 and type 2 diabetes, then excluding additional harmful effects on the cardiovascular system mediated by activation of the adrenergic system. Given that no biological rationale for a possible difference in cardiovascular effect of basal insulins has been proposed so far, available meta-analyses of publicly disclosed randomized controlled trials do not show any signal of increased risk of major cardiovascular events between the different basal insulin analogs. However, the number of available cardiovascular events in these trials is very small, preventing any clear-cut conclusion. The results of an ongoing clinical trial comparing glargine and degludec with regard to cardiovascular safety will provide definitive evidence. PMID:26203281

  5. Cardiovascular effects of basal insulins

    PubMed Central

    Mannucci, Edoardo; Giannini, Stefano; Dicembrini, Ilaria

    2015-01-01

    Basal insulin is an important component of treatment for both type 1 and type 2 diabetes. One of the principal aims of treatment in patients with diabetes is the prevention of diabetic complications, including cardiovascular disease. There is some evidence, although controversial, that attainment of good glycemic control reduces long-term cardiovascular risk in both type 1 and type 2 diabetes. The aim of this review is to provide an overview of the potential cardiovascular safety of the different available preparations of basal insulin. Current basal insulin (neutral protamine Hagedorn [NPH], or isophane) and basal insulin analogs (glargine, detemir, and the more recent degludec) differ essentially by various measures of pharmacokinetic and pharmacodynamic effects in the bloodstream, presence and persistence of peak action, and within-subject variability in the glucose-lowering response. The currently available data show that basal insulin analogs have a lower risk of hypoglycemia than NPH human insulin, in both type 1 and type 2 diabetes, then excluding additional harmful effects on the cardiovascular system mediated by activation of the adrenergic system. Given that no biological rationale for a possible difference in cardiovascular effect of basal insulins has been proposed so far, available meta-analyses of publicly disclosed randomized controlled trials do not show any signal of increased risk of major cardiovascular events between the different basal insulin analogs. However, the number of available cardiovascular events in these trials is very small, preventing any clear-cut conclusion. The results of an ongoing clinical trial comparing glargine and degludec with regard to cardiovascular safety will provide definitive evidence. PMID:26203281

  6. [Variable magnetic field of 8 Hz corrects the opioid system activity in mollusks behind the ferromagnetic screening].

    PubMed

    Temur'iants, N A; Kostiuk, A S

    2014-01-01

    The three phases of mollusk nociception alteration as a result of extended ferromagnetic screening combined with exposure to a variable magnetic field of 8 Hz correlated with phase changes in the opioid system activity (OSA) deduced from the naloxone action on the thermal avoidance response. On phase I, OSA inactivation was inhibited and, consequently, hyperalgesia progression was expedited. On phase II, OSA rose so that naloxone annulled completely the antinociceptive effect produced by the ferromagnetic screening. On phase III, OSA declined progressively, as naloxone merely reduced the antinociceptive effect because of apparently, growing OSA tolerance to the ferromagnetic screening. Phase I was absent when mollusks were exposed to the ferromagnetic screening and variable magnetic field; however, OSA changes on phases II and III were present. It was concluded that the variable magnetic field of 8 Hz can be used for correcting changes in the opioid system activity in mollusks behind the ferromagnetic screening. PMID:25163338

  7. Multiple pigmented basal cell carcinomas.

    PubMed

    Shoji, T; Lee, J; Hong, S H; Oh, C H; Kim, W K; Bhawan, J

    1998-04-01

    Basal cell carcinoma is the most common of all skin cancers and the most prevalent one among Caucasians. Rarely, these tumors are seen in other races. We report a 77-year-old Korean woman who presented with multiple darkly pigmented enlarging nodules on her scalp, face, trunk, and extremities. The patient had first noted a 6-mm pigmented lesion on her left eyebrow 10 years previously. Since then, other lesions had appeared in many locations on her body. She had been otherwise healthy and without a history of exposure to arsenic or radiation. There was no family history of skin cancer, xeroderma pigmentosum, or basal cell nevus syndrome. On physical examination, multiple darkly pigmented dome-shaped papules and nodules were present on her scalp, face, right forearm, lower abdomen, and inguinal areas. They ranged in size from 0.5 mm to 2 cm. The larger ones showed central ulceration. Multiple biopsy specimens from different sites showed pigmented basal cell carcinomas. Clinically, there was no evidence of nevus sebaceus, xeroderma pigmentosum, basal cell nevus syndrome, or immunodeficiency. Clinical workup including chest radiography, abdominal ultrasound, bone scan, and brain computerized axial tomography scan did not demonstrate primary or secondary tumors. The results of serologic and hematologic tests were also within normal limits. This is an unusual case report of multiple pigmented basal cell carcinomas in an Asian woman without any predisposing risk factors. PMID:9557792

  8. Improved molecular detection of Angiostrongylus cantonensis in mollusks and other environmental samples with a species-specific ITS1-based TaqMan assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Angiostrongylus cantonensis is the most common cause of human eosinophilic meningitis. Humans can become infected by ingesting food items contaminated with the third-stage infectious larvae released from infected mollusks as well as by ingesting mollusks or paratenic hosts carrying the infectious st...

  9. Kahalalides V–Y Isolated from a Hawaiian Collection of the Sacoglossan Mollusk Elysia rufescens

    PubMed Central

    Rao, Karumanchi V.; Na, MinKyun; Cook, Jennifer C.; Peng, Jiangnan; Matsumoto, Rae; Hamann, Mark T.

    2016-01-01

    Four new kahalalides, V (1), W (2), X (3), and Y (4), as well as six previously characterized kahalalides have been isolated from a two-year collection of the sacoglossan mollusk Elysia rufescens. Curiously, kahalalide B, previously isolated in high yield from E. rufescens, was found to be essentially absent from these collections despite identical collection sites and times with previous collections. In addition, kahalalide K, which to date has only been reported from Bryopsis sp., was found in this collection of E. rufescens, suggesting that the production of these metabolites could potentially be from a microbial association with the mollusk and algae, and this relationship is continuously evolving in response to changes in the environment and predation. The structures of new peptides have been established on the basis of extensive 1D and 2D NMR spectroscopic data analysis. Kahalalide V (1) was ascertained to be an acyclic derivative of kahalalide D (5), while kahalalide W (2) was determined to have a 4-hydroxy-L-proline residue instead of the proline in 5. The arginine residue of kahalalide X (3), an acyclic derivative of kahalalide C, was determined to have an L configuration. Kahalalide Y (4) was found to have an L-proline residue instead of the hydroxyproline in kahalalide K. It is clear from this collection of E. rufescens that the discovery of new kahalalide-related metabolites is still highly feasible. PMID:18407693

  10. Mobile Element Evolution Playing Jigsaw—SINEs in Gastropod and Bivalve Mollusks

    PubMed Central

    Matetovici, Irina; Sajgo, Szilard; Ianc, Bianca; Ochis, Cornelia; Bulzu, Paul; Popescu, Octavian; Damert, Annette

    2016-01-01

    SINEs (Short INterspersed Elements) are widely distributed among eukaryotes. Some SINE families are organized in superfamilies characterized by a shared central domain. These central domains are conserved across species, classes, and even phyla. Here we report the identification of two novel such superfamilies in the genomes of gastropod and bivalve mollusks. The central conserved domain of the first superfamily is present in SINEs in Caenogastropoda and Vetigastropoda as well as in all four subclasses of Bivalvia. We designated the domain MESC (Romanian for MElc—snail and SCoica—mussel) because it appears to be restricted to snails and mussels. The second superfamily is restricted to Caenogastropoda. Its central conserved domain—Snail—is related to the Nin-DC domain. Furthermore, we provide evidence that a 40-bp subdomain of the SINE V-domain is conserved in SINEs in mollusks and arthropods. It is predicted to form a stable stem-loop structure that is preserved in the context of the overall SINE RNA secondary structure in invertebrates. Our analysis also recovered short retrotransposons with a Long INterspersed Element (LINE)-derived 5′ end. These share the body and/or the tail with transfer RNA (tRNA)-derived SINEs within and across species. Finally, we identified CORE SINEs in gastropods and bivalves—extending the distribution range of this superfamily. PMID:26739168

  11. Mobile Element Evolution Playing Jigsaw - SINEs in Gastropod and Bivalve Mollusks.

    PubMed

    Matetovici, Irina; Sajgo, Szilard; Ianc, Bianca; Ochis, Cornelia; Bulzu, Paul; Popescu, Octavian; Damert, Annette

    2016-01-01

    SINEs (Short INterspersed Elements) are widely distributed among eukaryotes. Some SINE families are organized in superfamilies characterized by a shared central domain. These central domains are conserved across species, classes, and even phyla. Here we report the identification of two novel such superfamilies in the genomes of gastropod and bivalve mollusks. The central conserved domain of the first superfamily is present in SINEs in Caenogastropoda and Vetigastropoda as well as in all four subclasses of Bivalvia. We designated the domain MESC (Romanian for MElc-snail and SCoica-mussel) because it appears to be restricted to snails and mussels. The second superfamily is restricted to Caenogastropoda. Its central conserved domain-Snail-is related to the Nin-DC domain. Furthermore, we provide evidence that a 40-bp subdomain of the SINE V-domain is conserved in SINEs in mollusks and arthropods. It is predicted to form a stable stem-loop structure that is preserved in the context of the overall SINE RNA secondary structure in invertebrates. Our analysis also recovered short retrotransposons with a Long INterspersed Element (LINE)-derived 5' end. These share the body and/or the tail with transfer RNA (tRNA)-derived SINEs within and across species. Finally, we identified CORE SINEs in gastropods and bivalves-extending the distribution range of this superfamily. PMID:26739168

  12. Baseline trace metals in seagrass, algae, and mollusks in a southern Tyrrhenian ecosystem (Linosa Island, Sicily).

    PubMed

    Conti, Marcelo Enrique; Bocca, Beatrice; Iacobucci, Marta; Finoia, Maria Grazia; Mecozzi, Mauro; Pino, Anna; Alimonti, Alessandro

    2010-01-01

    Trace elements were analyzed in organisms collected at five sampling stations along coastal areas of Linosa Island, Sicily (southern Tyrrhenian Sea, Italy). Concentrations of Cd, Cr, Cu, Pb, and Zn were measured in Posidonia oceanica L. Delile tissues, the two brown algae Padina pavonica (L.) Thivy and Cystoseira sp., and the two gastropod mollusks Monodonta turbinata Born and Patella caerulea L. Seawater samples were also collected at each site to assess soluble metal concentrations and to gain relevant information on their bioaccumulation ability. Data were processed by multivariate techniques, such as principal component analysis (PCA) and linear discriminant analysis on PCA factors. The scoreplots obtained showed that the pollutant distribution is more significantly correlated with species than with sites. For seaweeds, P. oceanica was associated with higher Cd, Cu, and Zn levels; Padina species had higher Cr concentrations, and Cystoseira had higher Pb levels. For mollusks, Monodonta species had high concentrations of Cu and Cr and Patella species were associated with Cd. Some general metal bioaccumulation patterns are described but no one sampling site was more contaminated than the others. The hypothesis of Linosa island serving as a reference ecosystem for baseline trace metal levels in southern Tyrrhenian areas is indeed supported by the statistical comparison among other southern Tyrrhenian ecosystems performed with Kruskall Wallis and Mann-Whitney tests. For P. oceanica leaves, P. pavonica, M. turbinata, and P. caerulea, this study confirms their usefulness as possible cosmopolitan biomonitors of trace metals in marine Mediterranean areas. PMID:19458990

  13. [Diversity and abundance of mollusks in the sublittoral epifaunal community of Punta Patilla, Venezuela].

    PubMed

    Prieto, Antulio; Ruiz, Lilia J; García, Natividad

    2005-01-01

    The diversity of a sublittoral epifaunal mollusk community of Punta Patilla, Sucre State, Venezuela, was studied from September 1990 to September 1991. We identified 25 species (14 bivalves and 11 gastropods) of mollusks that inhabit gravel, soft sand and bottoms covered by Thalassia testudinum. Total diversity indices were H' = 3.42. J' = 0.74 and 1-D = 0.85. Monthly diversity reached its maximum in March 1991 (3.12 bits/ ind.), June 1991 (2.88 bits/ind.) and September 1991 (2.95 bits/ind.); minimum diversity was recorded in August 1991 (1.20 bits/ind.). A log series model showed a diversity index alpha = 4.56 for species abundance data and alpha = 3.11 for biomass data. The more abundant species were Chione cancellata, Anigona listeri, Chione granulata and Area zebra among the bivalves, and Chicoreus brevifrons, Turritella variegata and Phllonotus pomum among the gastropods (which present maximum biomass). The average total biomass (56.80 g/m2) is low when compared to reports from other tropical zones. PMID:17354426

  14. Baseline trace metals in gastropod mollusks from the Beagle Channel, Tierra del Fuego (Patagonia, Argentina).

    PubMed

    Conti, Marcelo Enrique; Stripeikis, Jorge; Finoia, Maria Grazia; Tudino, Mabel Beatriz

    2012-05-01

    With the aim to evaluate the mollusk Nacella (P)magellanica as biomonitor of elemental pollution in seawater of the Beagle Channel, more than one hundred individuals of the gastropod were sampled, separated in viscera and muscle, and then examined with respect to the accumulation of Cd, Cr, Cu, Ni, Pb and Zn. Collection was performed in seven strategic locations along 170 km of the coastal area of the Beagle Channel (Tierra del Fuego, Argentina) in two campaigns during 2005 and 2007. Samples of surrounding seawater in the different sites were obtained and tested for the same metals as well. The accumulation capacity of Nacella (P)magellanica and thus its aptitude as biomonitor, was evaluated through the calculus of the preconcentration factors of the metals assayed. A discussion involving the comparison with other mollusks previously tested will be given. Several statistical approaches able to analyze data with environmental purposes were applied. Non parametric univariate tests such as Kruskal-Wallis and Mann-Whitney were carried out to assess the changes of the metal concentrations with time (2005 and 2007) in each location. Multivariate methods (linear discriminant analysis on PCA factors) were also applied to obtain a more reliable site classification. Johnson's probabilistic method was carried out for comparison between different geographical areas. The possibility of employing these results as heavy metals' background levels of seawater from the Beagle Channel will be debated. PMID:22350107

  15. The first mollusk spätzle homolog gene in the clam, Paphia undulate.

    PubMed

    Yu, Mingjia; Zhang, Yuehuan; Tang, Xu; Ren, Jun; Zhang, Yang

    2015-12-01

    Spätzle, is the only identified endogenous Toll receptor ligand, plays a critical role in initiatinge innate immune responses and controlling dorsal-ventral axis formation in Drosophila. Here we identified the first spätzle gene homolog, Pu-Spz, in the marine mollusk Paphia undulate. The full-length of Pu-Spz cDNA is 1248 bp, including an open reading frame (ORF) of 702 bp, a 5'-untranslated region (UTR) of 26 bp and a 3'-UTR of 203 bp. The ORF encodes a 233-amino-acid protein with conserved domains; it includes a putative signal peptide and a C-terminal cystine-knot. Sequence alignment revealed that the cystine-knot domain of Pu-Spz contains six highly conserved Cys residues, which maintain a molecular conformation suitable for Toll receptor binding. Unlike Spätzle, Pu-Spz lacks a seventh Cys residue, which is essential for forming intermolecular disulfide bridge. Phylogenetic analysis revealed that Pu-Spz is closer to the homologs found in crustaceans than to those in the insect branch. Transcript abundance of Pu-Spz was increased after challenging P. undulate with either heat-killed Listeria monocytogenes or heat-killed Vibrio alginolyticus, suggesting Spätzle is involved in P. undulate host defense. Our results demonstrate convergent evolution of the spätzle-Toll system between the mollusk and arthropod lineages. PMID:26477575

  16. Experimental analysis and numerical modeling of mollusk shells as a three dimensional integrated volume.

    PubMed

    Faghih Shojaei, M; Mohammadi, V; Rajabi, H; Darvizeh, A

    2012-12-01

    In this paper, a new numerical technique is presented to accurately model the geometrical and mechanical features of mollusk shells as a three dimensional (3D) integrated volume. For this purpose, the Newton method is used to solve the nonlinear equations of shell surfaces. The points of intersection on the shell surface are identified and the extra interior parts are removed. Meshing process is accomplished with respect to the coordinate of each point of intersection. The final 3D generated mesh models perfectly describe the spatial configuration of the mollusk shells. Moreover, the computational model perfectly matches with the actual interior geometry of the shells as well as their exterior architecture. The direct generation technique is employed to generate a 3D finite element (FE) model in ANSYS 11. X-ray images are taken to show the close similarity of the interior geometry of the models and the actual samples. A scanning electron microscope (SEM) is used to provide information on the microstructure of the shells. In addition, a set of compression tests were performed on gastropod shell specimens to obtain their ultimate compressive strength. A close agreement between experimental data and the relevant numerical results is demonstrated. PMID:23137621

  17. Development of a loop-mediated isothermal amplification method for detection of Perkinsus spp. in mollusks.

    PubMed

    Feng, Chunyan; Wang, Caixia; Lin, Xiangmei; Zhang, Yongning; Lv, Jizhou; Deng, Junhua; Yuan, Xiangfen; Mei, Lin; Wu, Shaoqiang

    2013-05-27

    Perkinsus is a genus of unicellular protozoan parasite responsible for mass mortality of several commercially valuable mollusks. Surveillance and inspection of its epidemiology in the field calls for convenient and rapid detection methods. Here, a loop-mediated isothermal amplification (LAMP) assay was developed to detect the presence of Perkinsus spp. in mollusks. Specific LAMP primers were designed targeting the conserved internal transcribed spacer 2 (ITS-2) region of the rRNA gene of Perkinsus spp. Using ITS-2 recombinant plasmid as a template, we optimized the LAMP reaction system and conditions and then evaluated the analytical sensitivity and specificity of the assay. The LAMP assay was validated using clam samples collected from coastal areas in eastern China and oysters imported to China and compared with the traditional Ray's fluid thioglycollate culture method (RFTM). Our results showed that the LAMP detection method for Perkinsus was successful. The detection limit was 10 copies of plasmid DNA. Compared to the RFTM assay, the LAMP detection method was more sensitive (56 versus 52 positive out of 60 samples). P. olseni and P. marinus from infected hosts were successfully detected by this method. The LAMP method is rapid, sensitive, and specific for Perkinsus spp. detection, and could be used to screen for perkinsosis both on farms and at ports. PMID:23709467

  18. Aliens in Paradise. Boat density and exotic coastal mollusks in Moorea Island (French Polynesia).

    PubMed

    Ardura, Alba; Planes, Serge; Garcia-Vazquez, Eva

    2015-12-01

    Pacific islands are particularly vulnerable to the effects of invasive species. After habitat destruction or modification, invasive species are responsible for more biological extinctions than any other cause. Further, the rate of extinction of native species has been higher on islands than anywhere else in the world. Invasive species have also degraded native ecosystems. In order to detect exotic intertidal mollusk species, an extensive sampling around Moorea Island, a more or less unspoiled island surrounded by a rich coral reef habitat, has been developed considering that sampled points have different characteristics in wave exposure, algae coverage, type of substrate, distance to ports, distance to freshwater, distance sewage and boat traffic. Samples were DNA barcoded for unequivocal species assignation. The presence of five NIS among 26 species seems an important signal of introduction of alien biota in Moorea Island coast. However they were represented by a total of 38 individuals among 1487 mollusks (2.55%). While the distance to relatively big ports influenced directly species richness, the intensity of maritime traffic measured as boat density near sampling points was significantly associated with the frequency of exotic species. Other environmental factors did not show significant correlation with the frequency of exotics, suggesting that in an environment without big discontinuities, with little habitat modification, local boat traffic is the most influential factor in the spread of exotic species. This could be mitigated relatively easily by reducing boat density in local zones of ecological interest. PMID:26364683

  19. Basal cell carcinoma – diagnosis

    PubMed Central

    Bowszyc-Dmochowska, Monika; Strzelecka-Węklar, Daria; Dańczak-Pazdrowska, Aleksandra; Adamski, Zygmunt

    2013-01-01

    Basal cell carcinoma is the most common skin cancer in the Caucasian population. The cancer arises in sun exposed areas of the skin. The incidence of morbidity is high and it is still growing. The metastatic rate is low, but the enlarging tumor may cause severe tissue disfigurement and a poor cosmetic outcome. The diagnosis is usually clinical but there are many subtypes of this carcinoma and correct diagnosis is the clue to appropriate treatment of the lesion. The main problem in basal cell carcinoma management is the high recurrence rate. PMID:24592119

  20. Teachers Reflect Standards in Basals

    ERIC Educational Resources Information Center

    Gewertz, Catherine

    2012-01-01

    Dozens of teachers and literacy specialists from across the country hunkered down in Baltimore at round tables, with laptops, pens, and paper, intent on rewriting the collections that wield tremendous influence over the way millions of U.S. children learn literacy skills: the big-name basal readers. Hailing from 18 school districts in 11 states,…

  1. [Evolutionary regularities of somatic polyploidy expansion in salivary glands of gastropod mollusks. V. Subclasses Opisthobranchia and Pulmonata].

    PubMed

    Anisimov, A P; Ziumchenko, N E

    2012-01-01

    Salivary glands of 25 species of euthyneural gastropod mollusks (Opisthobranchia and Pulmonata) have been investigated by means of histochemical methods and DNA cytophotometry in nuclei of cells. The cells of three basic types are distinguished in glandular epithelim: granular cells (with glicoproteid granular inclusions), mucocytes-I (with sulfatic acid mucopolysaccharides) and mucocytes-II (with neutral and acid nonsulfatic polysaccharides and proteins) and so the epithelial ciliated cells and cells of the ducts. It was shown that glandular cells of salivary glands of all discovered mollusks' species are polyploid in different degree. The highest ploidy level estimated by means of DNA content in most of species is 64-128c. The giant polyploidy, attained to 4096c, is discovered in cells of salivary glands of Tritonia diomedea. The functional conditionality connected with features of feeding of different mollusk species and phylogenetic tendencies of expansion of somatic polyploidy in class Gastropoda are discussed. In comparison with allogenic, facultative and small polyploidy manifestation in Prosobranchia the obligatory polyploidization of high degree revealed in cells of salivary glands of Opisthobranchia and Pulmonata is consider to be the original cytological arogenesis. The probable causes of such differences are conneted with euthyneural type of organization of central nervous system and giant polyploidy of neurons in Opisthobranchia and Pulmonata mollusks. The causes, mechanisms and significance of such correlations are unclear for the present. PMID:22590930

  2. [Isolation of the cercaria Diplostomum phoxini (Faust, 1918) Arvy et Buttner, 1954 (Diplostomatidae) from fresh water mollusks of the Crimea].

    PubMed

    Sten'ko, R P

    1976-01-01

    Data on the biology and morphology of cercariae of Diplostomum phoxini (Faust, 1918) Arvy et Buttner, 1954 are given. The cercariae were found in Radix auricularia from the middle part of the Burulcha river (Ukranian SSR, Crimea). In November, 1974 the invasion extensity of mollusks was 16.3%. No cercariae were found in spring and summer samples. PMID:66655

  3. Vestigial prototroch in a basal nemertean, Carinoma tremaphoros (Nemertea; Palaeonemertea).

    PubMed

    Maslakova, S A; Martindale, M Q; Norenburg, J L

    2004-01-01

    Nemerteans have been alleged to belong to a protostome clade called the Trochozoa that includes mollusks, annelids, sipunculids, echiurids, and kamptozoans and is characterized by, among other things, the trochophore larva. The trochophore possesses a prototroch, a preoral belt of specialized ciliary cells, derived from the trochoblast cells. Nemertea is the only trochozoan phylum for which presence of the trochophore larva possessing a prototroch had never been shown. However, so little is known about nemertean larval development that comparing it with development of other trochozoans is difficult. Development in the nemertean clade Pilidiophora is via a highly specialized planktonic larva, the pilidium, and most of the larval body is lost during a drastic metamorphosis. Other nemerteans (hoplonemerteans and palaeonemerteans) lack a pilidium, and their development is direct, forming either an encapsulated or planktonic "planuliform" larva, producing a juvenile without a dramatic change in body plan. We show that early in the development of a member of a basal nemertean assemblage, the palaeonemertean Carinoma tremaphoros, large squamous cells cover the entire larval surface except for the apical and posterior regions. Although apical and posterior cells continue to divide, the large surface cells cleavage arrest and form a contorted preoral belt. Based on its position, cell lineage, and fate, we suggest that this belt corresponds to the prototroch of other trochozoans. Lack of differential ciliation obscures the presence of the prototroch in Carinoma, but differentiation of the trochoblasts is clearly manifested in their permanent cleavage arrest and ultimate degenerative fate. Our results allow a meaningful comparison between the development of nemerteans and other trochozoans. We review previous hypotheses of the evolution of nemertean development and suggest that a trochophore-like larva is plesiomorphic for nemerteans while a pilidium type of development with

  4. Uptake of polycyclic aromatic hydrocarbon compounds by the gills of the bivalve mollusk Elliptio complanata.

    PubMed

    Birdsall, K; Kukor, J J; Cheney, M A

    2001-02-01

    Polycyclic aromatic hydrocarbons (PAHs) and herbicides are important contaminants of world water systems with effects on aquatic organisms. The uptake of naphthalene, anthracene, and chrysene by gills of the bivalve mollusk Elliptio complanata was determined. Additionally, the effects of paraquat, atrazine, alachlor, 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4-dinitrophenol on the uptake of these compounds were also determined. The results indicate (1) the uptake of anthracene is approximately equivalent to that of chrysene and the uptake of either of these compounds is higher than that of naphthalene; (2) comparisons of uptakes with that of inulin, which occupies only extracellular space, show that all compounds studied are taken up; (3) the uptakes of naphthalene, anthracene, and chrysene are initially altered by the presence of herbicides such as paraquat, alachlor, 2,4-D, atrazine, and 2,4-dinitrophenol. PMID:11351430

  5. Radiocarbon dating of fossil mollusk shells in the Yucca Mountain region

    SciTech Connect

    Brennan, R.; Quade, J.

    1995-12-01

    Fossil mollusk shells from late Quaternary deposits in Southern Nevada were radiocarbon dated to determine the age of paleogroundwater discharge events and to establish minimum {sup 14}C ages of paleogroundwater. Shells of the terrestrial taxa Vallonia sp. and Succineidae returned {sup 14}C dates consistent with those on organic material in the same stratigraphic position. The aquatic taxa Gyraulus parvus and Gyraulus circumstratus returned the oldest dates within each unit samples. These results show that (1) fossil Vallonia and Succineidae are useful in dating deposits in which no other radiocarbon-datable material is available, and (2) Gyraulus sp. select micro habitats with the most {sup 14}C deficient water, providing minimum ages of groundwater in the area during the last glacial period.

  6. Activated Acinus boosts basal autophagy

    PubMed Central

    Nandi, Nilay; Tyra, Lauren K; Krämer, Helmut

    2015-01-01

    Acinus (Acn) is a nuclear protein that participates in the regulation of autophagy. Loss of Acn function prevents autophagy in starving cells. Conversely, Acn activation induces basal autophagy. This enhances the quality control functions of autophagy such as the removal of misfolded proteins, thereby reducing neurodegeneration and prolonging lifespan. Acn activity is enhanced by Akt1-mediated phosphorylation, which counteracts the cleavage of Acn by a caspase-3 homolog. PMID:27308482

  7. Hox and ParaHox gene expression in early body plan patterning of polyplacophoran mollusks

    PubMed Central

    Fritsch, Martin; Wollesen, Tim

    2016-01-01

    ABSTRACT Molecular developmental studies of various bilaterians have shown that the identity of the anteroposterior body axis is controlled by Hox and ParaHox genes. Detailed Hox and ParaHox gene expression data are available for conchiferan mollusks, such as gastropods (snails and slugs) and cephalopods (squids and octopuses), whereas information on the putative conchiferan sister group, Aculifera, is still scarce (but see Fritsch et al., 2015 on Hox gene expression in the polyplacophoran Acanthochitona crinita). In contrast to gastropods and cephalopods, the Hox genes in polyplacophorans are expressed in an anteroposterior sequence similar to the condition in annelids and other bilaterians. Here, we present the expression patterns of the Hox genes Lox5, Lox4, and Lox2, together with the ParaHox gene caudal (Cdx) in the polyplacophoran A. crinita. To localize Hox and ParaHox gene transcription products, we also investigated the expression patterns of the genes FMRF and Elav, and the development of the nervous system. Similar to the other Hox genes, all three Acr‐Lox genes are expressed in an anteroposterior sequence. Transcripts of Acr‐Cdx are seemingly present in the forming hindgut at the posterior end. The expression patterns of both the central class Acr‐Lox genes and the Acr‐Cdx gene are strikingly similar to those in annelids and nemerteans. In Polyplacophora, the expression patterns of the Hox and ParaHox genes seem to be evolutionarily highly conserved, while in conchiferan mollusks these genes are co‐opted into novel functions that might have led to evolutionary novelties, at least in gastropods and cephalopods. PMID:27098677

  8. Hox and ParaHox gene expression in early body plan patterning of polyplacophoran mollusks.

    PubMed

    Fritsch, Martin; Wollesen, Tim; Wanninger, Andreas

    2016-03-01

    Molecular developmental studies of various bilaterians have shown that the identity of the anteroposterior body axis is controlled by Hox and ParaHox genes. Detailed Hox and ParaHox gene expression data are available for conchiferan mollusks, such as gastropods (snails and slugs) and cephalopods (squids and octopuses), whereas information on the putative conchiferan sister group, Aculifera, is still scarce (but see Fritsch et al., 2015 on Hox gene expression in the polyplacophoran Acanthochitona crinita). In contrast to gastropods and cephalopods, the Hox genes in polyplacophorans are expressed in an anteroposterior sequence similar to the condition in annelids and other bilaterians. Here, we present the expression patterns of the Hox genes Lox5, Lox4, and Lox2, together with the ParaHox gene caudal (Cdx) in the polyplacophoran A. crinita. To localize Hox and ParaHox gene transcription products, we also investigated the expression patterns of the genes FMRF and Elav, and the development of the nervous system. Similar to the other Hox genes, all three Acr-Lox genes are expressed in an anteroposterior sequence. Transcripts of Acr-Cdx are seemingly present in the forming hindgut at the posterior end. The expression patterns of both the central class Acr-Lox genes and the Acr-Cdx gene are strikingly similar to those in annelids and nemerteans. In Polyplacophora, the expression patterns of the Hox and ParaHox genes seem to be evolutionarily highly conserved, while in conchiferan mollusks these genes are co-opted into novel functions that might have led to evolutionary novelties, at least in gastropods and cephalopods. PMID:27098677

  9. Basal body structure in Trichonympha.

    PubMed

    Guichard, Paul; Gönczy, Pierre

    2016-01-01

    Trichonympha is a symbiotic flagellate of many species of termites and of the wood-feeding cockroach. Remarkably, this unicellular organism harbors up to over ten thousand flagella on its surface, which serve to propel it through the viscous environment of the host hindgut. In the 1960s, analysis of resin-embedded Trichonympha samples by electron microscopy revealed that the basal bodies that give rise to these flagella are exceptionally long, with a proximal, cartwheel-bearing, region some 50 times longer than that of regular centrioles. In recent years, this salient feature has prompted the analysis of the 3D architecture of Trichonympha basal bodies in the native state using cryo-electron tomography. The resulting ~40 Å resolution map of the basal body proximal region revealed a number of novel features that may be conserved in centrioles of other systems. These include proximal-distal polarity of the pinhead structure that links the cartwheel to centriolar microtubules, as well as of the linker between the A and the C microtubules. Moreover, this work demonstrated that the cartwheel is made of stacked ring-like structures that likely each comprise 18 molecules of SAS-6 proteins. PMID:26937279

  10. Discourse Types in Canadian Basal Reading Programs.

    ERIC Educational Resources Information Center

    Murphy, Sharon

    This study examined the authorship and discourse types of Canadian basal anthologies to determine whether the lingering centrality of the basal anthology in Canadian programs controls students and teachers by controlling language and reading. Each selection within five Canadian basal series (Gage Expressways II, Ginn Journeys, Holt Impressions,…

  11. Late miocene-pliocene paleoclimatic evolution documented by terrestrial mollusk populations in the western Chinese Loess Plateau.

    PubMed

    Li, Fengjiang; Wu, Naiqin; Rousseau, Denis-Didier; Dong, Yajie; Zhang, Dan; Pei, Yunpeng

    2014-01-01

    The Neogene eolian deposits in the Chinese Loess Plateau (CLP) are one of the most useful continental deposits for understanding climatic changes. To decipher Late Neogene paleoclimatic changes in the CLP, we present a terrestrial mollusk record spanning the time interval between 7.1 and 3.5 Ma from the western CLP. The results indicate four stages of paleoclimatic evolution: From 7.1 to 6.2 Ma, cold and dry climatic conditions prevailed as evidenced by high values of the total number of cold-aridiphilous (CA) mollusk species and by low values of all of the thermo-humidiphilous (TH) mollusk indices. From 6.2 to 5.4 Ma, the climate remained cold and dry but was not quite as dry as during the preceding phase, as indicated by the dominance of CA mollusks and more TH species and individuals. From 5.4 to 4.4 Ma, a warm and moist climate prevailed, as indicated by high values of the TH species and individuals and by the sparsity of CA species and individuals. From 4.4 to 3.5 Ma, all of the CA indices increased significantly and maintained high values; all of the TH indices exhibit high values from 4.4 to 4.0 Ma, an abrupt decrease from 4.0 Ma and a further increase from 3.7 Ma. The CA species of Cathaica pulveraticula, Cathaica schensiensis, and Pupopsis retrodens are only identified in this stage, indicating that the CA species were diversified and that the climate was becoming drier. Moreover, the CA mollusk group exhibits considerable diversity from 7.1 to 5.4 Ma when a cold, dry climate prevailed; whereas the diversity of the TH group was high during the relatively warm, wet interval from 5.4 to 4.4 Ma. This indicates that variations in the diversity of the CA and TH mollusk groups were closely related to climatic changes during the Late Miocene to Pliocene. PMID:24752586

  12. Late Miocene–Pliocene Paleoclimatic Evolution Documented by Terrestrial Mollusk Populations in the Western Chinese Loess Plateau

    PubMed Central

    Li, Fengjiang; Wu, Naiqin; Rousseau, Denis-Didier; Dong, Yajie; Zhang, Dan; Pei, Yunpeng

    2014-01-01

    The Neogene eolian deposits in the Chinese Loess Plateau (CLP) are one of the most useful continental deposits for understanding climatic changes. To decipher Late Neogene paleoclimatic changes in the CLP, we present a terrestrial mollusk record spanning the time interval between 7.1 and 3.5 Ma from the western CLP. The results indicate four stages of paleoclimatic evolution: From 7.1 to 6.2 Ma, cold and dry climatic conditions prevailed as evidenced by high values of the total number of cold-aridiphilous (CA) mollusk species and by low values of all of the thermo-humidiphilous (TH) mollusk indices. From 6.2 to 5.4 Ma, the climate remained cold and dry but was not quite as dry as during the preceding phase, as indicated by the dominance of CA mollusks and more TH species and individuals. From 5.4 to 4.4 Ma, a warm and moist climate prevailed, as indicated by high values of the TH species and individuals and by the sparsity of CA species and individuals. From 4.4 to 3.5 Ma, all of the CA indices increased significantly and maintained high values; all of the TH indices exhibit high values from 4.4 to 4.0 Ma, an abrupt decrease from 4.0 Ma and a further increase from 3.7 Ma. The CA species of Cathaica pulveraticula, Cathaica schensiensis, and Pupopsis retrodens are only identified in this stage, indicating that the CA species were diversified and that the climate was becoming drier. Moreover, the CA mollusk group exhibits considerable diversity from 7.1 to 5.4 Ma when a cold, dry climate prevailed; whereas the diversity of the TH group was high during the relatively warm, wet interval from 5.4 to 4.4 Ma. This indicates that variations in the diversity of the CA and TH mollusk groups were closely related to climatic changes during the Late Miocene to Pliocene. PMID:24752586

  13. "Basal Cell Blanche": A Diagnostic Maneuver to Increase Early Detection of Basal Cell Carcinomas.

    PubMed

    Quach, Olivia Leigh; Barry, Megan; Roberts Cruse, Allison; Wilson, Barbara B

    2016-01-01

    Basal cell carcinomas represent one of the most common skin cancers and often present initially in the primary care setting. Subtle basal cell carcinomas may be difficult to detect, and early detection of these carcinomas remains important in limiting patient morbidity. In this article, we present a simple diagnostic maneuver, "basal cell blanche," to increase early detection of basal cell carcinomas. PMID:27170799

  14. [The influence of the degree of infestation with trematode parthenites on the structure of penial glands in the mollusks Littorina saxatilis of different age].

    PubMed

    Ganzha, E V; Starunova, Z I

    2011-01-01

    Histological and confocal microscopy studies of the structure of penial glands in the Littorina saxatilis males were carried out. The examined mollusks belong to two age groups and were at different stages of spontaneous infection with a trematode from the pygmaeus species group (Microphallus piriformes). Based on comparative analysis of microscopic sections of copulative organs in infested and non-infested mollusks, data on the modifications in histological structure ofpenial glands were obtained. From these data we can suggest that the infestation have an influence on all parts of the gland. Decrease of secret production and reduction of muscular capsule (down to its disappearance) were observed. We suppose that changes in the penial glands structure prevent their normal functioning. In the mollusks infested on reaching the sexual maturity, gradual reduction of distal part of reproductive system was observed, while in the mollusks infested before the sexual maturity, development of ancillary part of reproductive system was blocked. PMID:22384680

  15. The basal bodies of Chlamydomonas reinhardtii.

    PubMed

    Dutcher, Susan K; O'Toole, Eileen T

    2016-01-01

    The unicellular green alga, Chlamydomonas reinhardtii, is a biflagellated cell that can swim or glide. C. reinhardtii cells are amenable to genetic, biochemical, proteomic, and microscopic analysis of its basal bodies. The basal bodies contain triplet microtubules and a well-ordered transition zone. Both the mother and daughter basal bodies assemble flagella. Many of the proteins found in other basal body-containing organisms are present in the Chlamydomonas genome, and mutants in these genes affect the assembly of basal bodies. Electron microscopic analysis shows that basal body duplication is site-specific and this may be important for the proper duplication and spatial organization of these organelles. Chlamydomonas is an excellent model for the study of basal bodies as well as the transition zone. PMID:27252853

  16. Migraine attacks the Basal Ganglia

    PubMed Central

    2011-01-01

    Background With time, episodes of migraine headache afflict patients with increased frequency, longer duration and more intense pain. While episodic migraine may be defined as 1-14 attacks per month, there are no clear-cut phases defined, and those patients with low frequency may progress to high frequency episodic migraine and the latter may progress into chronic daily headache (> 15 attacks per month). The pathophysiology of this progression is completely unknown. Attempting to unravel this phenomenon, we used high field (human) brain imaging to compare functional responses, functional connectivity and brain morphology in patients whose migraine episodes did not progress (LF) to a matched (gender, age, age of onset and type of medication) group of patients whose migraine episodes progressed (HF). Results In comparison to LF patients, responses to pain in HF patients were significantly lower in the caudate, putamen and pallidum. Paradoxically, associated with these lower responses in HF patients, gray matter volume of the right and left caudate nuclei were significantly larger than in the LF patients. Functional connectivity analysis revealed additional differences between the two groups in regard to response to pain. Conclusions Supported by current understanding of basal ganglia role in pain processing, the findings suggest a significant role of the basal ganglia in the pathophysiology of the episodic migraine. PMID:21936901

  17. Middle pleistocene mollusks from St. Lawrence Island and their significance for the paleo-oceanography of the Bering Sea

    USGS Publications Warehouse

    Hopkins, D.M.; Rowland, R.W.; Patton, W.W., Jr.

    1972-01-01

    Drift, evidently of Illinoian age, was deposited on St. Lawrence Island at the margin of an ice cap that covered the highlands of the Chukotka Peninsula of Siberia and spread far eastward on the continental shelf of northern Bering Sea. Underlying the drift on the northwestward part of the island are mollusk-bearing beds deposited during the Kotzebuan Transgression. A comparison of mollusk faunas from St. Lawrence Island, Chukotka Peninsula, and Kotzebue Sound suggests that the present northward flow through Bering and Anadyr Straits was reversed during the Kotzebuan Transgression. Cold arctic water penetrated southward and southwestward bringing an arctic fauna to the Gulf of Anadyr. Warmer Pacific water probably entered eastern Bering Sea, passed eastward and northeastward around eastern and northern St. Lawrence Island, and then became entrained in the southward currents that passed through Anadyr Strait. ?? 1972.

  18. Prevalence and intensity of infection with third stage larvae of Angiostrongylus cantonensis in mollusks from Northeast Thailand.

    PubMed

    Tesana, Smarn; Srisawangwong, Tuanchai; Sithithaworn, Paiboon; Laha, Thewarach; Andrews, Ross

    2009-06-01

    Prevalences and intensity of infection with Angiostrongylus cantonensis third stage larvae were examined in mollusks to determine whether they are potential intermediate hosts in eight provinces, northeast Thailand. Mollusk samples were collected from 24 reservoirs (3 reservoirs/province) in close to human cases during the previous year. Six out of 24 localities and 9 (3 new record species) out of 27 species were found with the infection. The highest intensity in infected species was found to be only one or two snails, whereas the majority had very low or no infection. The highest density was found in Pila pesmei and the lowest in Pila polita. The edible snails, P. polita, P. pesmei, and Hemiplecta distincta have the potential to transmit A. cantonensis to man. The varying density levels of larvae in infected snails may reflect observed variation in symptoms of people who traditionally eat a raw snail dish. PMID:19478262

  19. The endemic mollusks reveal history of the long-lived Pliocene Lake Slavonia in NW Croatia

    NASA Astrophysics Data System (ADS)

    Mandic, Oleg; Kurečić, Tomislav; Neubauer, Thomas A.; Harzhauser, Mathias

    2015-04-01

    The present investigation deals with the fossil mollusk record of the long-lived Pliocene Lake Slavonia settled in the southern Pannonian Basin. The samples originate from Vukomeričke gorice, a low hill-range situated north of the Kupa River in the area between the towns of Zagreb, Sisak and Karlovac in NW Croatia. Representing the SW margin of the Lake Slavonia the freshwater deposits alternate there with the alluvial series, providing altogether about 400-m-thick, Pliocene continental succession, known in literature by informal name Paludina beds (acc. to a junior synonym of Viviparus). The endemic fauna of the Lake Slavonia became particularly well-known in the late 19th century after Melchior Neumayr demonstrated that the gradual evolutionary change of the mollusk phenotypes toward more complex morphology represents a function of adaptation to environmental change in the paleolake. Even Charles Darwin commented that result as by far the best case which I have ever met with, showing the direct influence of the conditions of life on the organization. The deposition in the Lake Slavonia (~4.5 to ~1.8 Ma) coincides with the Pliocene Climate Optimum (PCO), but captures also the transition into the Pleistocene climate marked by the initial Ice Age pulse at 2.59 Ma. The increase of polar temperatures resulted during PCO in a significant melting of the ice caps leading to a global sea level rise tentatively getting up to 25 m higher than today. Coincidence of the climate and geodynamic settings in southeastern Europe provided conditions supporting extended settlement of lacustrine environments including Lake Slavonia, Lake Kosovo, Lake Transylvania and Lake Dacia, all characterized by explosive adaptive radiations of viviparid snails. In particular, the latter adaptive radiations resulted in the regional phylostratigraphy of Lake Slavonia Viviparus species enabling excellent stratigraphic control for the investigated deposits. Hence, based on this evidence, the

  20. Specific features of the planarian Dugesia tigrina regeneration and mollusk Helix albescens nociception under weak electromagnetic shielding

    NASA Astrophysics Data System (ADS)

    Temur'yants, N. A.; Demtsun, N. A.; Kostyuk, A. S.; Yarmolyuk, N. S.

    2012-12-01

    It has been demonstrated that weak electromagnetic shielding stimulates regeneration in the planarian Dugesia tigrina, the stimulating intensity being dependent on both the initial state of the animals, which is determined by season, and their functional asymmetry. As has been shown, the effect of a weak electromagnetic field induces phasic changes in the nociceptive sensitivity of the mollusk Helix albescens: an increase in the sensitivity to a thermal stimulus is replaced by the development of the hypalgesic effect.

  1. Historical changes of sediments and mollusk assemblages in the Gulf of Batabanó (Caribbean Sea) in the twentieth century.

    PubMed

    Armenteros, Maickel; Díaz-Asencio, Misael; Fernández-Garcés, Raúl; Eriksson, Mats; Alonso-Hernández, Carlos; Sanchez-Cabeza, Joan-Albert

    2012-08-01

    The first paleoecological reconstruction of the biogeochemical conditions of the Gulf of Batabanó, Caribbean Sea was performed from (210)Pb-dated sediment cores. Depth profiles of 20 major elements and trace metals, organic compounds, grain size, and mollusk assemblage composition were determined from 9 stations encompassing unconsolidated sediments in the gulf. Spatial heterogeneity was evident for the geochemistry of sediments and for the mollusk assemblage composition. Our reconstruction indicates that pollution is not a critical threat to the ecosystem, although a slight historical increase of lead enrichment factor was detected probably due to long-range atmospheric fallout. Mollusk assemblages were composed by 168 species belonging to 59 families and no temporal trends in the species diversity or assemblage composition were detected, suggesting no depletion of diversity or habitat loss. Other signals of habitat loss such as changes in organic budget or increase of fine sediment fraction were absent or weak. Nitrogen retained in sediments changed by <1% in the century, indicating no historical events of eutrophication or oligotrophication in the gulf. Historical decrease of fine sediment fraction in the eastern sector would be linked to modifications in sedimentation rate, land use, and/or particle transport from the shelf border; this also suggests that both sectors have different sedimentary dynamics. Although, on theoretical grounds, historical fishery may have caused deleterious ecosystem effects by overexploitation of spiny lobster stocks, no evidence of habitat degradation or loss, caused by fisheries, could be detected. PMID:21881898

  2. Mollusk collecting and environmental change during the Prehistoric Period in the Mariana Islands

    NASA Astrophysics Data System (ADS)

    Amesbury, J. R.

    2007-12-01

    Archaeological research in the Mariana Islands has revealed changes in mollusk collecting during the Prehistoric Period (approximately 1500 BC to AD 1521). The earliest people at Tumon Bay, Guam and Chalan Piao, Saipan collected mostly bivalves, especially the arc clam Anadara antiquata. After several hundred years, they no longer collected A. antiquata, but collected smaller bivalves instead. By AD 1000, they collected mostly gastropods, primarily the coral reef species Strombus gibberulus gibbosus. One possible explanation is that the people preferred the large arc clam but overharvested it until they were forced to eat the smaller bivalves and then the snails. However, recent evidence in the form of mangrove wood and mangrove pollen supports another explanation, one of non-anthropogenic environmental change. In this case, the relative sea-level decline, which took place in the Marianas within the last 4,000 years, caused the demise of mangrove habitats and of the arc clam at Tumon Bay, Guam and Chalan Piao, Saipan. As mangrove habitats were diminished by sea-level decline, collecting effort shifted to coral reefs, and S. gibberulus gibbosus was harvested throughout the remainder of the Prehistoric Period and into the Historic Period. Southern Guam is the only area in the Marianas in which A. antiquata increased in abundance during the Prehistoric Period. The same types of evidence, mangrove wood and mangrove pollen, indicate that, in contrast to the situation at Tumon Bay and Chalan Piao, mangroves increased in abundance in southern Guam.

  3. The LBP/BPI multigenic family in invertebrates: Evolutionary history and evidences of specialization in mollusks.

    PubMed

    Baron, Olga Lucia; Deleury, Emeline; Reichhart, Jean-Marc; Coustau, Christine

    2016-04-01

    LBPs (lipopolysaccharide binding proteins) and BPIs (bactericidal permeability increasing proteins) are important proteins involved in defense against bacterial pathogens. We recently discovered a novel biocidal activity of a LBP/BPI from the gastropod Biomphalaria glabrata and demonstrated its role in parental immune protection of eggs, highlighting the importance of LBP/BPIs in invertebrate immunity. Here we characterize four additional LBP/BPI from B. glabrata, presenting conserved sequence architecture and exon-intron structure. Searches of invertebrate genomes revealed that existence of LBP/BPIs is not a conserved feature since they are absent from phyla such as arthropods and platyhelminths. Analyses of LBP/BPI transcripts from selected mollusk species showed recent parallel duplications in some species, including B. glabrata. In this snail species, LBP/BPI members vary in their expression tissue localization as well as their change in expression levels after immune challenges (Gram-negative bacterium; Gram-positive bacterium or yeast). These results, together with the predicted protein features provide evidences of functional specialization of LBP/BPI family members in molluscs. PMID:26608112

  4. Responses to magnetic stimuli recorded in peripheral nerves in the marine nudibranch mollusk Tritonia diomedea.

    PubMed

    Pavlova, Galina A; Glantz, Raymon M; Dennis Willows, A O

    2011-10-01

    Prior behavioral and neurophysiological studies provide evidence that the nudibranch mollusk Tritonia orients to the earth's magnetic field. Earlier studies of electrophysiological responses in certain neurons of the brain to changing ambient magnetic fields suggest that although certain identified brain cells fire impulses when the ambient field is changed, these neuron somata and their central dentritic and axonal processes are themselves not primary magnetic receptors. Here, using semi-intact animal preparations from which the brain was removed, we recorded from peripheral nerve trunks. Using techniques to count spikes in individual nerves and separately also to identify, then count individual axonal spikes in extracellular records, we found both excitatory and inhibitory axonal responses elicited by changes in the direction of ambient earth strength magnetic fields. We found responses in nerves from many locations throughout the body and in axons innervating the body wall and rhinophores. Our results indicate that primary receptors for geomagnetism in Tritonia are not focally concentrated in any particular organ, but appear to be widely dispersed in the peripheral body tissues. PMID:21717186

  5. Interspecific variation of metal concentrations in three bivalve mollusks from Galicia.

    PubMed

    Saavedra, Y; González, A; Fernández, P; Blanco, J

    2004-10-01

    There has been growing concern about the inflow of metals to the coastal areas because they can be toxic to aquatic and human life. Some studies have demonstrated the existence of species-specific differences in the metal concentrations of mollusks. We compared metal concentrations between Mytilus galloprovincialis, used as a water quality indicator, and two other bivalve species collected for human consumption (Venerupis pullastra and Cerastoderma edule) in different locations on the Galician coast (northwest Spain). M. galloprovincialis was found to be the best zinc and lead accumulator, whereas silver and arsenic were preferentially accumulated by V. pullastra and chromium and nickel by C. edule. Bivalve concentrations of mercury, cadmium, chromium, arsenic, silver, and zinc appeared to be linearly related to environmental concentrations, but this was not the case with copper, nickel, and lead in some species, which indicated that there is a nonlinear accumulation of these metals or an influence of the environmental conditions on species accumulation. The relationship between metal concentration in mussels and in the two other species varied with the metal and the species. In some cases the correlation was high, making it possible to use mussels as bioindicators for the other species. In other cases the correlation was moderate or low, therefore rendering mussels of little or no use in predicting the metal concentrations in the two other species. PMID:15386128

  6. Calcium concretions: Evidence of contaminant exposure in three species of marine mollusks

    SciTech Connect

    Benyi, S.J.

    1994-12-31

    Researchers have hypothesized that calcium concretions identified in the kidney of quahogs collected along an urban pollution gradient may result from the sequestering of water- and sediment-borne contaminants. The objectives of this study were to determine if renal calcium deposition was a response to contaminants and to assess calcium concretions as a marker of exposure. Renal calcium concretions in three species of marine mollusks (northern quahog (Mercenaria mercenaria), eastern oyster (Crassostrea virginica) and softshell (Mya arenaria)) were quantified after a 28-day laboratory exposure to a reference or contaminated sediment (Black Rock Harbor, BRH). Hemolymph calcium, the source of calcium for concretions, was measured weekly to detect a calcium concentration change when and if calcium concretions were deposited in the kidney. Results indicated no effect of contaminated sediment on the hemolymph calcium of any species tested. The response to the contaminants, manifested as renal calcium concretions, was species-specific. Renal concretions were not found in the oysters. However, renal calcium concretions increased from 3.7% of reference-exposed to 52.4% of BRH-exposed softshells. While renal calcium concretions were found in the majority of quahogs, there were more renal concretions in BRH-exposed quahogs than the reference exposed quahogs and the concretions were larger. The increase in renal calcium concretions in quahogs and softshells exposed to contaminants in sediment indicates that renal calcium concretion formation may be associated with contaminant exposure in these species.

  7. Irradiated bivalve mollusks: Use of EPR spectroscopy for identification and dosimetry

    NASA Astrophysics Data System (ADS)

    Alberti, Angelo; Chiaravalle, Eugenio; Fuochi, Piergiorgio; Macciantelli, Dante; Mangiacotti, Michele; Marchesani, Giuliana; Plescia, Elena

    2011-12-01

    High energy radiation treatment of foodstuff for microbial control and shelf-life extension is being used in many countries. However, for consumer protection and information, the European Union has adopted the Directives 1999/2/EC and 1999/3/EC to harmonize the rules concerning the treatment and trade of irradiated foods in EU countries. Among the validated methods to detect irradiated foods the EU directives also include Electron Paramagnetic Resonance (EPR/ESR) spectroscopy.We describe herein the use of EPR for identification of four species of bivalve mollusks, i.e. brown Venus shells (Callista chione), clams (Tapes semidecussatus), mussels (Mytilus galloprovincialis) and oysters (Ostrea edulis) irradiated with 60Co γ-rays. EPR could definitely identify irradiated seashells due to the presence of long-lived free radicals, primarily CO2-, CO33-, SO2- and SO3- radical anions. The presence of other organic free radicals, believed to originate from conchiolin, a scleroprotein present in the shells, was also ascertained. The use of one of these radicals as a marker for irradiation of brown Venus shells and clams can be envisaged. We also propose a dosimetric protocol for the reconstruction of the administered dose in irradiated oysters.

  8. A hyperpolarization-activated inward current alters swim frequency of the pteropod mollusk Clione limacina.

    PubMed

    Pirtle, Thomas J; Willingham, Kyle; Satterlie, Richard A

    2010-12-01

    The pteropod mollusk, Clione limacina, exhibits behaviorally relevant swim speed changes that occur within the context of the animal's ecology. Modulation of C. limacina swimming speed involves changes that occur at the network and cellular levels. Intracellular recordings from interneurons of the swim central pattern generator show the presence of a sag potential that is indicative of the hyperpolarization-activated inward current (I(h)). Here we provide evidence that I(h) in primary swim interneurons plays a role in C. limacina swimming speed control and may be a modulatory target. Recordings from central pattern generator swim interneurons show that hyperpolarizing current injection produces a sag potential that lasts for the duration of the hyperpolarization, a characteristic of cells possessing I(h). Following the hyperpolarizing current injection, swim interneurons also exhibit postinhibitory rebound (PIR). Serotonin enhances the sag potential of C. limacina swim interneurons while the I(h) blocker, ZD7288, reduces the sag potential. Furthermore, a negative correlation was found between the amplitude of the sag potential and latency to PIR. Because latency to PIR was previously shown to influence swimming speed, we hypothesize that I(h) has an effect on swimming speed. The I(h) blocker, ZD7288, suppresses swimming in C. limacina and inhibits serotonin-induced acceleration, evidence that supports our hypothesis. PMID:20696266

  9. Stress detection in bivalve mollusk using non-invasive bioelectric monitoring of myoneural behavior

    SciTech Connect

    Morgan, E.L.; Hardison, B.S.; Dawson, V.K.; Waller, D.; Waller, W.T.; Dickson, K.L.; Allen, H.J.

    1995-12-31

    Few studies have demonstrated cause-and-effect linkages between extrinsic environmental factors and intrinsic bioelectric action potentials of bivalve mollusk using non-invasive, non-destructive approaches. A non-invasive, external probe configuration and detection system, similar to one used previously with native unionids, was developed for continuously monitoring bioelectric activities of clams and mussels. Using remote probes and differential amplifiers, bioelectric activities were recorded for cardiac, adductor, siphon and foot responses using a computer equipped with integrating software. To test if remote, non-invasive probes would detect similar information to that recorded by invasive needle electrodes, two individuals of zebra mussel (Dreissenia polymorpha), and Asiatic clam (Corbicula fluminea) were each configured with two sets of probes. One set was inserted between the valves and along the inside surface of the shelf; the other set was positioned remotely about the outside margins of the valves. Signal validation was made by simultaneously recording bioelectric responses for the same animal from both sets of probes. In preliminary stress tests monitored bivalves were subjected to changes in temperatures over 2 to 3 hr intervals from ambient to potentially lethal levels (20 to 30 C for zebra, 25 C to 40 C for corbicula). Dramatic increases resulted in both number and amplitude of cardiac events as temperature increased. Planned studies will use this approach to evaluate bivalve myoneural behavior patterns in response to chemical and non-chemical stimuli.

  10. Functional Neuroanatomy of the Basal Ganglia

    PubMed Central

    Lanciego, José L.; Luquin, Natasha; Obeso, José A.

    2012-01-01

    The “basal ganglia” refers to a group of subcortical nuclei responsible primarily for motor control, as well as other roles such as motor learning, executive functions and behaviors, and emotions. Proposed more than two decades ago, the classical basal ganglia model shows how information flows through the basal ganglia back to the cortex through two pathways with opposing effects for the proper execution of movement. Although much of the model has remained, the model has been modified and amplified with the emergence of new data. Furthermore, parallel circuits subserve the other functions of the basal ganglia engaging associative and limbic territories. Disruption of the basal ganglia network forms the basis for several movement disorders. This article provides a comprehensive account of basal ganglia functional anatomy and chemistry and the major pathophysiological changes underlying disorders of movement. We try to answer three key questions related to the basal ganglia, as follows: What are the basal ganglia? What are they made of? How do they work? Some insight on the canonical basal ganglia model is provided, together with a selection of paradoxes and some views over the horizon in the field. PMID:23071379

  11. Striatal plasticity and basal ganglia circuit function.

    PubMed

    Kreitzer, Anatol C; Malenka, Robert C

    2008-11-26

    The dorsal striatum, which consists of the caudate and putamen, is the gateway to the basal ganglia. It receives convergent excitatory afferents from cortex and thalamus and forms the origin of the direct and indirect pathways, which are distinct basal ganglia circuits involved in motor control. It is also a major site of activity-dependent synaptic plasticity. Striatal plasticity alters the transfer of information throughout basal ganglia circuits and may represent a key neural substrate for adaptive motor control and procedural memory. Here, we review current understanding of synaptic plasticity in the striatum and its role in the physiology and pathophysiology of basal ganglia function. PMID:19038213

  12. sine oculis in basal Metazoa.

    PubMed

    Bebenek, Ilona G; Gates, Ruth D; Morris, Joshua; Hartenstein, Volker; Jacobs, David K

    2004-07-01

    We report the recovery of homologs of Six1/2/sine oculis (so), a homeodomain-containing member of the Six-gene family, from a diverse set of basal Metazoa, including representatives of the poriferan classes Demospongia, Calcarea and Hexactinellida, the cnidarian classes Hydrozoa, Scyphozoa and Anthozoa, as well as a ctenophore. so sequences were also recovered from a platyhelminth, an echiurid and two bivalve molluscs, members of the super-phyletic group Lophotrochozoa. In the case of the platyhelminth, multiple distinct so sequences were recovered, as well as a member of the related group Six4/5/D-Six4. Extended sequences of the so gene were recovered from the demosponge, Haliclona sp., and the scyphozoan Aurelia aurita via PCR, and 3' RACE. The affinities of all recovered sequences were assessed using a parsimony analysis based on both nucleic and amino acid sequence and using successive character weighting. Our results indicate that so is highly conserved across the animal kingdom. Preliminary expression data for Aurelia reveal that transcripts of the so homolog are present in the manubrium as well as in the rhopalia, which contain the statocyst and eyes, in the free-swimming ephyra and juvenile stages of these jellyfish. PMID:15221378

  13. Toughening mechanisms in laminated composites: A biomimetic study in mollusk shells

    NASA Astrophysics Data System (ADS)

    Kamat, Shekhar Shripad

    2000-10-01

    Mollusk shells can be described as structural biocomposite materials composed of a mineral (aragonite) and a continuous, albeit minor, organic (protein) component. The conch shell, Strombus Gigas, has intermediate strength and high fracture toughness. The high fracture toughness is a result of enhanced energy dissipation during crack propagation due to delamination, crack bridging, frictional sliding etc. A theoretical and experimental study was conducted on the crack bridging mechanisms operative in the shell. Four-point bend tests were conducted. Acoustic emission and post-mortem dye penetrants were used to characterize the crack propagation, together with conventional fractography. A two layer composite configuration is seen in the shells, with the tough and weak layers having a toughness ratio of ˜4 (Ktough = 2.2MPam1/2). This toughness ratio is a requisite for multiple cracking in the weak layer. A theoretical shear lag analysis of the crack bridging phenomena in the tough layer is shown to lead to a bridging law for the crack wake of the form of p = betau1/2 (p is the bridging traction for a crack opening u, with beta, being a constant of proportionality). Finite element analysis yielded a value of beta = 630 Nmm-5/2 and ucritical = 5 mum for the bridging law parameters. In a nonlinear fracture mechanics phenomenology, these values are relevant material parameters, rather than a critical stress intensity factor. The work of fracture for unnotched specimens is three orders of magnitude higher than mineral aragonite, and is demonstrated numerically incorporating the toughening mechanisms in the shell. Similar structural adaptations have been observed and studied in the red abalone shell, haliotis rufescens and the spines of the sea urchin, Heterocentrotus trigonarius. The toughening mechanisms seen in these shells give insight into structural design needs of brittle matrix composites (BMC) as well as conventional structural ceramics.

  14. Jackknife-corrected parametric bootstrap estimates of growth rates in bivalve mollusks using nearest living relatives.

    PubMed

    Dexter, Troy A; Kowalewski, Michał

    2013-12-01

    Quantitative estimates of growth rates can augment ecological and paleontological applications of body-size data. However, in contrast to body-size estimates, assessing growth rates is often time-consuming, expensive, or unattainable. Here we use an indirect approach, a jackknife-corrected parametric bootstrap, for efficient approximation of growth rates using nearest living relatives with known age-size relationships. The estimate is developed by (1) collecting a sample of published growth rates of closely related species, (2) calculating the average growth curve using those published age-size relationships, (3) resampling iteratively these empirically known growth curves to estimate the standard errors and confidence bands around the average growth curve, and (4) applying the resulting estimate of uncertainty to bracket age-size relationships of the species of interest. This approach was applied to three monophyletic families (Donacidae, Mactridae, and Semelidae) of mollusk bivalves, a group characterized by indeterministic shell growth, but widely used in ecological, paleontological, and geochemical research. The resulting indirect estimates were tested against two previously published geochemical studies and, in both cases, yielded highly congruent age estimates. In addition, a case study in applied fisheries was used to illustrate the potential of the proposed approach for augmenting aquaculture management practices. The resulting estimates of growth rates place body size data in a constrained temporal context and confidence intervals associated with resampling estimates allow for assessing the statistical uncertainty around derived temporal ranges. The indirect approach should allow for improved evaluation of diverse research questions, from sustainability of industrial shellfish harvesting to climatic interpretations of stable isotope proxies extracted from fossil skeletons. PMID:24071629

  15. Readiness in the Basal Reader: An Update.

    ERIC Educational Resources Information Center

    Perkins, Pamela

    A study examined two 1989 basal reading series' (published by McGraw Hill and Holt) readiness/priming sequences in order to ascertain the theoretical bases of each and then compared the findings with those of an earlier study. All pages of the readiness/priming sequence student texts and workbooks of both basal reading series were analyzed using…

  16. Modern basal insulin analogs: An incomplete story

    PubMed Central

    Singh, Awadhesh Kumar; Gangopadhyay, Kalyan Kumar

    2014-01-01

    The currently available basal insulin does not completely mimic the endogenous insulin secretion. This has continued to promote the search for ideal basal insulin. The newer basal insulin have primarily focused on increasing the duration of action, reducing variability, and reducing the incidence of hypoglycemia, particularly nocturnal. However, the changing criteria of hypoglycemia within a short span of a few years along with the surprising introduction of major cardiac events as another outcome measure has not only clouded the assessment of basal insulin but has also polarized opinion worldwide about the utility of the newer basal insulin. A critical review of both the pre and post FDA analysis of all the basal insulin in this article attempts to clear some of the confusion surrounding the issues of hypoglycemia and glycemic control. This article also discusses all the trials and meta-analysis done on all the current basal insulin available along with their head-to-head comparison with particular attention to glycemic control and hypoglycemic events including severe and nocturnal hypoglycemia. This in-depth analysis hopes to provide a clear interpretation of the various analyses available in literature at this point of time thereby acting as an excellent guide to the readers in choosing the most appropriate basal insulin for their patient. PMID:25364672

  17. Modern basal insulin analogs: An incomplete story.

    PubMed

    Singh, Awadhesh Kumar; Gangopadhyay, Kalyan Kumar

    2014-11-01

    The currently available basal insulin does not completely mimic the endogenous insulin secretion. This has continued to promote the search for ideal basal insulin. The newer basal insulin have primarily focused on increasing the duration of action, reducing variability, and reducing the incidence of hypoglycemia, particularly nocturnal. However, the changing criteria of hypoglycemia within a short span of a few years along with the surprising introduction of major cardiac events as another outcome measure has not only clouded the assessment of basal insulin but has also polarized opinion worldwide about the utility of the newer basal insulin. A critical review of both the pre and post FDA analysis of all the basal insulin in this article attempts to clear some of the confusion surrounding the issues of hypoglycemia and glycemic control. This article also discusses all the trials and meta-analysis done on all the current basal insulin available along with their head-to-head comparison with particular attention to glycemic control and hypoglycemic events including severe and nocturnal hypoglycemia. This in-depth analysis hopes to provide a clear interpretation of the various analyses available in literature at this point of time thereby acting as an excellent guide to the readers in choosing the most appropriate basal insulin for their patient. PMID:25364672

  18. The basal ganglia communicate with the cerebellum.

    PubMed

    Bostan, Andreea C; Dum, Richard P; Strick, Peter L

    2010-05-01

    The basal ganglia and cerebellum are major subcortical structures that influence not only movement, but putatively also cognition and affect. Both structures receive input from and send output to the cerebral cortex. Thus, the basal ganglia and cerebellum form multisynaptic loops with the cerebral cortex. Basal ganglia and cerebellar loops have been assumed to be anatomically separate and to perform distinct functional operations. We investigated whether there is any direct route for basal ganglia output to influence cerebellar function that is independent of the cerebral cortex. We injected rabies virus (RV) into selected regions of the cerebellar cortex in cebus monkeys and used retrograde transneuronal transport of the virus to determine the origin of multisynaptic inputs to the injection sites. We found that the subthalamic nucleus of the basal ganglia has a substantial disynaptic projection to the cerebellar cortex. This pathway provides a means for both normal and abnormal signals from the basal ganglia to influence cerebellar function. We previously showed that the dentate nucleus of the cerebellum has a disynaptic projection to an input stage of basal ganglia processing, the striatum. Taken together these results provide the anatomical substrate for substantial two-way communication between the basal ganglia and cerebellum. Thus, the two subcortical structures may be linked together to form an integrated functional network. PMID:20404184

  19. Nevoid Basal Cell Carcinoma Syndrome (Gorlin Syndrome).

    PubMed

    Bresler, Scott C; Padwa, Bonnie L; Granter, Scott R

    2016-06-01

    Nevoid basal cell carcinoma syndrome, or basal cell nevus syndrome (Gorlin syndrome), is a rare autosomal dominantly inherited disorder that is characterized by development of basal cell carcinomas from a young age. Other distinguishing clinical features are seen in a majority of patients, and include keratocystic odontogenic tumors (formerly odontogenic keratocysts) as well as dyskeratotic palmar and plantar pitting. A range of skeletal and other developmental abnormalities are also often seen. The disorder is caused by defects in hedgehog signaling which result in constitutive pathway activity and tumor cell proliferation. As sporadic basal cell carcinomas also commonly harbor hedgehog pathway aberrations, therapeutic agents targeting key signaling constituents have been developed and tested against advanced sporadically occurring tumors or syndromic disease, leading in 2013 to FDA approval of the first hedgehog pathway-targeted small molecule, vismodegib. The elucidation of the molecular pathogenesis of nevoid basal cell carcinoma syndrome has resulted in further understanding of the most common human malignancy. PMID:26971503

  20. Heavy metal levels in marine mollusks from areas with, or without, mining activities along the Gulf of California, Mexico.

    PubMed

    Cadena-Cárdenas, Lázaro; Méndez-Rodríguez, Lía; Zenteno-Savín, Tania; García-Hernández, Jaqueline; Acosta-Vargas, Baudilio

    2009-07-01

    To assess the safety for human consumption of commercially important bivalves harvested from areas with or without mining activities, we compared the levels of heavy metals in mollusks collected from different coastal environments along the Gulf of California. We sampled the mussel Mytilus edulis and the clams Laevicardium elatum and Megapitaria squalida (June 2004) and the clam Chione californiensis (November 2006). Concentrations of cadmium, lead, nickel, zinc, iron, copper, and manganese in the soft tissue of the mollusks were measured by atomic absorption spectrophotometry. Based on dry weight, the highest average concentrations of iron, copper, and cadmium were found in clams from Loreto (572, 181, and 4.66 mg/kg, respectively); that of nickel, in mussels from San Luquitas (12.2 mg/kg); that of zinc, both in mussels from San Luquitas and in clams from Golfo de Santa Clara (94.3 and 91.8 mg/kg, respectively); and those of lead and manganese in clams from the Golfo de Santa Clara (9.2 and 3.68 mg/kg, respectively). Although mollusks were taken from coastal areas of the Gulf of California, which are considered to be contaminated by mining activities, the heavy metals in the sediments apparently were in a chemical form that had low bioavailability for the bivalves feeding in those areas. The interplay of oceanographic conditions and the chemical composition of anthropogenic inputs into the environment is not well understood. Thus, these factors or their interaction could potentially result in increased concentration and bioavailability of such metals in areas without effluent generated by mining activities. PMID:18825444

  1. Structural, functional, and evolutionary aspects of galectins in aquatic mollusks: From a sweet tooth to the Trojan horse

    PubMed Central

    Vasta, GR; Feng, C; Bianchet, MA; Bachvaroff, TR; Tasumi, S

    2015-01-01

    Galectins constitute a conserved and widely distributed lectin family characterized by their binding affinity for β-galactosides and a unique binding site sequence motif in the carbohydrate recognition domain (CRD). In spite of their structural conservation, galectins display a remarkable functional diversity, by participating in developmental processes, cell adhesion and motility, regulation of immune homeostasis, and recognition of glycans on the surface of viruses, bacteria and protozoan parasites. In contrast with mammals, and other vertebrate and invertebrate taxa, the identification and characterization of bona fide galectins in aquatic mollusks has been relatively recent. Most of the studies have focused on the identification and domain organization of galectin-like transcripts or proteins in diverse tissues and cell types, including hemocytes, and their expression upon environmental or infectious challenge. Lectins from the eastern oyster Crassostrea virginica, however, have been characterized in their molecular, structural and functional aspects and some notable features have become apparent in the galectin repertoire of aquatic mollusks. These including less diversified galectin repertoires and different domain organizations relative to those observed in vertebrates, carbohydrate specificity for blood group oligosaccharides, and up regulation of galectin expression by infectious challenge, a feature that supports their proposed role(s) in innate immune responses. Although galectins from some aquatic mollusks have been shown to recognize microbial pathogens and parasites and promote their phagocytosis, they can also selectively bind to phytoplankton components, suggesting that they also participate in uptake and intracellular digestion of microalgae. In addition, the experimental evidence suggests that the protozoan parasite Perkinsus marinus has co-evolved with the oyster host to be selectively recognized by the oyster hemocyte galectins over algal food

  2. Structural, functional, and evolutionary aspects of galectins in aquatic mollusks: From a sweet tooth to the Trojan horse.

    PubMed

    Vasta, G R; Feng, C; Bianchet, M A; Bachvaroff, T R; Tasumi, S

    2015-09-01

    Galectins constitute a conserved and widely distributed lectin family characterized by their binding affinity for β-galactosides and a unique binding site sequence motif in the carbohydrate recognition domain (CRD). In spite of their structural conservation, galectins display a remarkable functional diversity, by participating in developmental processes, cell adhesion and motility, regulation of immune homeostasis, and recognition of glycans on the surface of viruses, bacteria and protozoan parasites. In contrast with mammals, and other vertebrate and invertebrate taxa, the identification and characterization of bona fide galectins in aquatic mollusks has been relatively recent. Most of the studies have focused on the identification and domain organization of galectin-like transcripts or proteins in diverse tissues and cell types, including hemocytes, and their expression upon environmental or infectious challenge. Lectins from the eastern oyster Crassostrea virginica, however, have been characterized in their molecular, structural and functional aspects and some notable features have become apparent in the galectin repertoire of aquatic mollusks. These including less diversified galectin repertoires and different domain organizations relative to those observed in vertebrates, carbohydrate specificity for blood group oligosaccharides, and up regulation of galectin expression by infectious challenge, a feature that supports their proposed role(s) in innate immune responses. Although galectins from some aquatic mollusks have been shown to recognize microbial pathogens and parasites and promote their phagocytosis, they can also selectively bind to phytoplankton components, suggesting that they also participate in uptake and intracellular digestion of microalgae. In addition, the experimental evidence suggests that the protozoan parasite Perkinsus marinus has co-evolved with the oyster host to be selectively recognized by the oyster hemocyte galectins over algal food

  3. Metastatic Basal Cell Carcinoma Accompanying Gorlin Syndrome

    PubMed Central

    Bilir, Yeliz; Gokce, Erkan; Ozturk, Banu; Deresoy, Faik Alev; Yuksekkaya, Ruken; Yaman, Emel

    2014-01-01

    Gorlin-Goltz syndrome or basal cell nevus syndrome is an autosomal dominant syndrome characterized by skeletal anomalies, numerous cysts observed in the jaw, and multiple basal cell carcinoma of the skin, which may be accompanied by falx cerebri calcification. Basal cell carcinoma is the most commonly skin tumor with slow clinical course and low metastatic potential. Its concomitance with Gorlin syndrome, resulting from a mutation in a tumor suppressor gene, may substantially change morbidity and mortality. A 66-year-old male patient with a history of recurrent basal cell carcinoma was presented with exophthalmus in the left eye and the lesions localized in the left lateral orbita and left zygomatic area. His physical examination revealed hearing loss, gapped teeth, highly arched palate, and frontal prominence. Left orbital mass, cystic masses at frontal and ethmoidal sinuses, and multiple pulmonary nodules were detected at CT scans. Basal cell carcinoma was diagnosed from biopsy of ethmoid sinus. Based on the clinical and typical radiological characteristics (falx cerebri calcification, bifid costa, and odontogenic cysts), the patient was diagnosed with metastatic skin basal cell carcinoma accompanied by Gorlin syndrome. Our case is a basal cell carcinoma with aggressive course accompanying a rarely seen syndrome. PMID:25506011

  4. The Basal Ganglia-Circa 1982

    NASA Technical Reports Server (NTRS)

    Mehler, William R.

    1981-01-01

    Our review has shown that recent studies with the new anterograde and retrograde axon transport methods have confirmed and extended our knowledge of the projection of the basal ganglia and clarified their sites of origin. They have thrown new light on certain topographic connectional relationships and revealed several new reciprocal connections between constituent nuclei of the basal ganglia. Similarly, attention has been drawn to the fact that there have also been many new histochemical techniques introduced in recent years that are now providing regional biochemical overlays for connectional maps of the central nervous system, especially regions in, or interconnecting with, the basal ganglia. However, although these new morphological biochemical maps are very complex and technically highly advanced, our understanding of the function controlled by the basal ganglia still remains primitive. The reader who is interested in some new ideas of the functional aspects of the basal ganglia is directed to Nauta's proposed conceptual reorganization of the basal ganglia telencephalon and to Marsden's more clinically orientated appraisal of the unsolved mysteries of the basal ganglia participation in the control of movement.

  5. Thermodynamic significance of human basal metabolism

    NASA Astrophysics Data System (ADS)

    Wang, Cuncheng

    1993-06-01

    The human basal state, a non-equilibrium steady state, is analysed in this paper in the light of the First and Second Laws of Thermodynamics whereby the thermodynamic significance of the basal metabolic rate and its distinction to the dissipation function and exergy loss are identified. The analysis demonstrates the correct expression of the effects of the blood flow on the heat balance in a human-body bio-heat model and the relationship between the basal metabolic rate and the blood perfusion.

  6. Basal encephalocele and morning glory syndrome.

    PubMed Central

    Caprioli, J; Lesser, R L

    1983-01-01

    Basal encephaloceles are often associated with other midline anomalies such as hypertelorism, broad nasal root, cleft lip, and cleft palate. Optic disc anomalies such as pallor, dysplasia, optic pit, coLoboma, and megalopapilla have been reported to occur in patients with basal encephalocele We report a case of a child with a sphenoethmoidal encephalocele and morning glory syndrome of the optic nerve. The presence of such optic nerve anomalies with facial midline anomalies should alert the clinician to the possible presence of a basal encephalocele. Images PMID:6849854

  7. Exploring errors in paleoclimate proxy reconstructions using Monte Carlo simulations: paleotemperature from mollusk and coral geochemistry

    NASA Astrophysics Data System (ADS)

    Carré, M.; Sachs, J. P.; Wallace, J. M.; Favier, C.

    2012-03-01

    Quantitative reconstructions of the past climate statistics from geochemical coral or mollusk records require quantified error bars in order to properly interpret the amplitude of the climate change and to perform meaningful comparisons with climate model outputs. We introduce here a more precise categorization of reconstruction errors, differentiating the error bar due to the proxy calibration uncertainty from the standard error due to sampling and variability in the proxy formation process. Then, we propose a numerical approach based on Monte Carlo simulations with surrogate proxy-derived climate records. These are produced by perturbing a known time series in a way that mimics the uncertainty sources in the proxy climate reconstruction. A freely available algorithm, MoCo, was designed to be parameterized by the user and to calculate realistic systematic and standard errors of the mean and the variance of the annual temperature, and of the mean and the variance of the temperature seasonality reconstructed from marine accretionary archive geochemistry. In this study, the algorithm is used for sensitivity experiments in a case study to characterize and quantitatively evaluate the sensitivity of systematic and standard errors to sampling size, stochastic uncertainty sources, archive-specific biological limitations, and climate non-stationarity. The results of the experiments yield an illustrative example of the range of variations of the standard error and the systematic error in the reconstruction of climate statistics in the Eastern Tropical Pacific. Thus, we show that the sample size and the climate variability are the main sources of the standard error. The experiments allowed the identification and estimation of systematic bias that would not otherwise be detected because of limited modern datasets. Our study demonstrates that numerical simulations based on Monte Carlo analyses are a simple and powerful approach to improve the understanding of the proxy records

  8. Residues and chiral signatures of organochlorine pesticides in mollusks from the coastal regions of the Yangtze River Delta: source and health risk implication.

    PubMed

    Zhou, Shanshan; Tang, Qiaozhi; Jin, Meiqing; Liu, Weiping; Niu, Lili; Ye, Hui

    2014-11-01

    The residues and enantiomeric fractions of organochlorine pesticides (OCPs) were measured in 11 mollusk species collected from the coastal areas along the Yangtze River Delta to evaluate the status, potential sources, and health risks of pollution in these areas. The concentrations of DDTs, HCHs, and chlordanes ranged from 6.22 to 398.19, 0.66-7.11, and 0.14-4.08 ng g(-1) based on wet weight, respectively; DDTs and HCHs have the highest values, globally. The DDTs increased and the HCHs decreased compared to historical data. Both the box-and-whisker plots and the one-way ANOVA tests indicated that the OCP levels varied little between sampling locations and organism species. The compositions of the DDTs and HCHs suggested a cocktail input pattern of fresh and weathered technical products. The comparative EF values for the α-HCH between the sediments and mollusks, as well as the lack of any discernible difference in the relative proportions of HCH isomers among different species from the same sampling site implied that the HCH residues in the mollusks came directly from the surrounding environment. However, the biotransformation of DDTs in mollusks cannot be precluded. The assessments performed based on several available guidelines suggested that although no significant human health risks were associated with the dietary intake of OCPs, the concentrations of DDTs exceeded the maximum residual limits of China and many developed nations. Moreover, an increased lifetime cancer risk from dietary exposure to either DDTs or HCHs remains a possibility. Because non-racemic OCP residues are common in the mollusk samples, our results suggest a need to further explore the levels and toxicity of the chiral contaminants in mollusks and other foodstuff to develop the human risk assessment framework based on chiral signatures. PMID:25113182

  9. Plant basal resistance to nematodes: an update.

    PubMed

    Holbein, Julia; Grundler, Florian M W; Siddique, Shahid

    2016-03-01

    Most plant-parasitic nematodes are obligate biotrophs feeding on the roots of their hosts. Whereas ectoparasites remain on the root surface and feed on the outer cell layers, endoparasitic nematodes enter the host to parasitize cells around or within the central cylinder. Nematode invasion and feeding causes tissue damage which may, in turn, lead to the activation of host basal defence responses. Hitherto, research interests in plant-nematode interaction have emphasized effector-triggered immunity rather than basal plant defence responses. However, some recent investigations suggest that basal defence pathways are not only activated but also play an important role in determining interaction outcomes. In this review we discuss the major findings and point out future directions to dissect the molecular mechanisms underlying plant basal defence to nematodes further. PMID:26842982

  10. A high-elevation MIS 5 hydrologic record using mollusks and ostracodes from Snowmass Village, Colorado, USA

    NASA Astrophysics Data System (ADS)

    Sharpe, Saxon E.; Bright, Jordon

    2014-11-01

    Sediments containing terrestrial and aquatic mollusks and ostracodes from the Ziegler Reservoir fossil site (2705 m elevation) near Snowmass Village, Colorado, span ~ 130-87 ka (MIS 5e through 5b). The southeastern area of the site where taxa were recovered was a relatively fresh, shallow, well-vegetated wetland during MIS 5e through 5c time, approximately 2 m deep, with a total dissolved solids value of ~ 200-1000 mg L- 1. The wetland was seasonally or annually variable and groundwater discharged along the margins of the bounding moraine. Groundwater likely contributed solutes to the system and may have contributed 18O-enriched water. Based on stable isotopes from ostracode calcite (δ18OOST and δ13COST), seasonal evaporation occurred and the dissolved inorganic carbon pool was unexpectedly enriched in 13C. The mollusk and ostracode faunas changed little across the MIS 5e/5d/5c boundaries, whereas a distinct change in the ostracode fauna occurred between the deposition of Unit 11 and Unit 13, which corresponds in time to the MIS 5c/5b boundary, indicating some combination of increased surface and/or groundwater flow, a decrease in water temperature, and a freshening and a possible deepening of the wetland.

  11. Multiple Beneficial Lipids Including Lecithin Detected in the Edible Invasive Mollusk Crepidula fornicata from the French Northeastern Atlantic Coast

    PubMed Central

    Dagorn, Flore; Buzin, Florence; Couzinet-Mossion, Aurélie; Decottignies, Priscilla; Viau, Michèle; Rabesaotra, Vony; Barnathan, Gilles; Wielgosz-Collin, Gaëtane

    2014-01-01

    The invasive mollusk Crepidula fornicata, occurring in large amounts in bays along the French Northeastern Atlantic coasts, may have huge environmental effects in highly productive ecosystems where shellfish are exploited. The present study aims at determining the potential economic value of this marine species in terms of exploitable substances with high added value. Lipid content and phospholipid (PL) composition of this mollusk collected on the Bourgneuf Bay were studied through four seasons. Winter specimens contained the highest lipid levels (5.3% dry weight), including 69% of PLs. Phosphatidylcholine (PC) was the major PL class all year, accounting for 63.9% to 88.9% of total PLs. Consequently, the winter specimens were then investigated for PL fatty acids (FAs), and free sterols. Dimethylacetals (DMAs) were present (10.7% of PL FA + DMA mixture) revealing the occurrence of plasmalogens. More than forty FAs were identified, including 20:5n-3 (9.4%) and 22:6n-3 (7.3%) acids. Fourteen free sterols were present, including cholesterol at 31.3% of the sterol mixture and about 40% of phytosterols. These data on lipids of C. fornicata demonstrate their positive attributes for human nutrition and health. The PL mixture, rich in PC and polyunsaturated FAs, offers an interesting alternative source of high value-added marine lecithin. PMID:25532566

  12. Characterization of Three Tetrabromobisphenol-S Derivatives in Mollusks from Chinese Bohai Sea: A Strategy for Novel Brominated Contaminants Identification

    PubMed Central

    Liu, Ai-feng; Tian, Yong; Yin, Nuo-ya; Yu, Miao; Qu, Guang-bo; Shi, Jian-bo; Du, Yu-guo; Jiang, Gui-bin

    2015-01-01

    Identification of novel brominated contaminants in the environment, especially the derivatives and byproducts of brominated flame retardants (BFRs), has become a wide concern because of their adverse effects on human health. Herein, we qualitatively and quantitatively identified three byproducts of tetrabromobisphenol-S bis(2,3-dibromopropyl ether) (TBBPS-BDBPE), including TBBPS mono(allyl ether) (TBBPS-MAE), TBBPS mono(2-bromoallyl ether) (TBBPS-MBAE) and TBBPS mono(2,3-dibromopropyl ether) (TBBPS-MDBPE) as novel brominated contaminants. Meanwhile, the mass spectra and analytical method for determination of TBBPS-BDBPE byproducts were presented for the first time. The detectable concentrations (dry weight) of TBBPS-MAE, TBBPS-MBAE and TBBPS-MDBPE were in the ranges 28–394 μg/g in technical TBBPS-BDBPE and 0.1–4.1 ng/g in mollusks collected from the Chinese Bohai Sea. The detection frequencies in mollusk samples were 5%, 39%, 95% for TBBPS-MAE, TBBPS-MBAE and TBBPS-MDBPE, respectively, indicating their prevailing in the environment. The results showed that they could be co-produced and leaked into the environment with production process, and might be more bioaccumulative and toxic than TBBPS-BDBPE. Therefore, the production and use of TBBPS derivatives lead to unexpected contamination to the surrounding environment. This study also provided an effective approach for identification of novel contaminants in the environment with synthesized standards and Orbitrap high resolution mass spectrometry. PMID:26130450

  13. Characterization of Three Tetrabromobisphenol-S Derivatives in Mollusks from Chinese Bohai Sea: A Strategy for Novel Brominated Contaminants Identification

    NASA Astrophysics Data System (ADS)

    Liu, Ai-Feng; Tian, Yong; Yin, Nuo-Ya; Yu, Miao; Qu, Guang-Bo; Shi, Jian-Bo; Du, Yu-Guo; Jiang, Gui-Bin

    2015-07-01

    Identification of novel brominated contaminants in the environment, especially the derivatives and byproducts of brominated flame retardants (BFRs), has become a wide concern because of their adverse effects on human health. Herein, we qualitatively and quantitatively identified three byproducts of tetrabromobisphenol-S bis(2,3-dibromopropyl ether) (TBBPS-BDBPE), including TBBPS mono(allyl ether) (TBBPS-MAE), TBBPS mono(2-bromoallyl ether) (TBBPS-MBAE) and TBBPS mono(2,3-dibromopropyl ether) (TBBPS-MDBPE) as novel brominated contaminants. Meanwhile, the mass spectra and analytical method for determination of TBBPS-BDBPE byproducts were presented for the first time. The detectable concentrations (dry weight) of TBBPS-MAE, TBBPS-MBAE and TBBPS-MDBPE were in the ranges 28-394 μg/g in technical TBBPS-BDBPE and 0.1-4.1 ng/g in mollusks collected from the Chinese Bohai Sea. The detection frequencies in mollusk samples were 5%, 39%, 95% for TBBPS-MAE, TBBPS-MBAE and TBBPS-MDBPE, respectively, indicating their prevailing in the environment. The results showed that they could be co-produced and leaked into the environment with production process, and might be more bioaccumulative and toxic than TBBPS-BDBPE. Therefore, the production and use of TBBPS derivatives lead to unexpected contamination to the surrounding environment. This study also provided an effective approach for identification of novel contaminants in the environment with synthesized standards and Orbitrap high resolution mass spectrometry.

  14. [Secondary metabolites, lethality and antimicrobial activity of extracts from three corals and three marine mollusks from Sucre, Venezuela].

    PubMed

    Ordaz, Gabriel; D'Armas, Haydelba; Yáñez, Dayanis; Hernández, Juan; Camacho, Angel

    2010-06-01

    The study of biochemical activity of extracts obtained from marine organisms is gaining interest as some have proved to have efficient health or industrial applications. To evaluate lethality and antimicrobial activities, some chemical tests were performed on crude extracts of the octocorals Eunicea sp., Muricea sp. and Pseudopterogorgia acerosa and the mollusks Pteria colymbus, Phyllonotus pomum and Chicoreus brevifrons, collected in Venezuelan waters. The presence of secondary metabolites like alkaloids, unsaturated sterols and pentacyclic triterpenes in all invertebrates, was evidenced. Additionally, sesquiterpenlactones, saponins, tannins, cyanogenic and cardiotonic glycosides were also detected in some octocoral extracts, suggesting that biosynthesis of these metabolites is typical in this group. From the lethality bioassays, all extracts resulted lethal to Artemia salina (LC50<1000 microg/ml) with an increased of lethal activity with exposition time. P. pomum extract showed the highest lethality rate (LC50=46.8 microg/ml). Compared to the octocorals, mollusks extracts displayed more activity and a greater action spectrum against different bacterial strains, whereas octocorals also inhibited some fungi strains growth. Staphylococcus aureus was the most susceptible to the antimicrobial power of the extracts (66.7%), whereas Pseudomonas aeruginosa, Candida albicans and Aspergillus niger were not affected. The antibiosis shown by marine organisms extracts indicates that some of their biosynthesized metabolites are physiologically active, and may have possible cytotoxic potential or as a source of antibiotic components. PMID:20527468

  15. Heavy metal effects on cellular shape changes, cleavage, and larval development of the marine gastropod mollusk, (Ilyanassa obsoleta Say)

    SciTech Connect

    Conrad, G.W.

    1988-07-01

    The spawning areas for many marine invertebrates are in intertidal zones which can be exposed to surface water run-off containing heavy metals. The cellular shape changes and cleavage patterns of Ilyanassa embryos greatly resemble those of bivalve mollusks, such as Mytilus edulis, that occur in the same intertidal areas. Determining the concentrations of heavy metals tolerated by the molluscan embryos inhabiting such clam and mussel beds therefore is of some economic significance. Moreover, such research may providedata on the heavy metal effects on the cytoskeleton. There is increasing evidence that components of the cytoskeleton, directly or indirectly, are targets for toxic agents. Polar lobe formation is a cellular shape change that resembles cytokinesis. It is seen in the fertilized eggs of many marine mollusks. Recent data with inorganic and organic Ca/sup 2 +/ antagonists suggest that both polar lobe formation and cytokinesis utilize Ca/sup 2 +/ released from sequestered, intracellular sites. Both of these cellular constrictions are associated with microfilaments and are preceded by activation steps requiring microtubules. The data presented below suggest that several heavy metals affect the microfilament-dependent steps.

  16. Automatic basal slice detection for cardiac analysis

    NASA Astrophysics Data System (ADS)

    Paknezhad, Mahsa; Marchesseau, Stephanie; Brown, Michael S.

    2016-03-01

    Identification of the basal slice in cardiac imaging is a key step to measuring the ejection fraction (EF) of the left ventricle (LV). Despite research on cardiac segmentation, basal slice identification is routinely performed manually. Manual identification, however, has been shown to have high inter-observer variability, with a variation of the EF by up to 8%. Therefore, an automatic way of identifying the basal slice is still required. Prior published methods operate by automatically tracking the mitral valve points from the long-axis view of the LV. These approaches assumed that the basal slice is the first short-axis slice below the mitral valve. However, guidelines published in 2013 by the society for cardiovascular magnetic resonance indicate that the basal slice is the uppermost short-axis slice with more than 50% myocardium surrounding the blood cavity. Consequently, these existing methods are at times identifying the incorrect short-axis slice. Correct identification of the basal slice under these guidelines is challenging due to the poor image quality and blood movement during image acquisition. This paper proposes an automatic tool that focuses on the two-chamber slice to find the basal slice. To this end, an active shape model is trained to automatically segment the two-chamber view for 51 samples using the leave-one-out strategy. The basal slice was detected using temporal binary profiles created for each short-axis slice from the segmented two-chamber slice. From the 51 successfully tested samples, 92% and 84% of detection results were accurate at the end-systolic and the end-diastolic phases of the cardiac cycle, respectively.

  17. Epidemiology of basal-like breast cancer

    PubMed Central

    Millikan, Robert C.; Newman, Beth; Tse, Chiu-Kit; Moorman, Patricia G.; Conway, Kathleen; Smith, Lisa V.; Labbok, Miriam H.; Geradts, Joseph; Bensen, Jeannette T.; Jackson, Susan; Nyante, Sarah; Livasy, Chad; Carey, Lisa; Earp, H. Shelton; Perou, Charles M.

    2008-01-01

    Risk factors for the newly identified “intrinsic” breast cancer subtypes (luminal A, luminal B, basal-like and human epidermal growth factor receptor 2-positive/estrogen receptor-negative) were determined in the Carolina Breast Cancer Study, a population-based, case–control study of African-American and white women. Immunohistochemical markers were used to subtype 1,424 cases of invasive and in situ breast cancer, and case subtypes were compared to 2,022 controls. Luminal A, the most common subtype, exhibited risk factors typically reported for breast cancer in previous studies, including inverse associations for increased parity and younger age at first full-term pregnancy. Basal-like cases exhibited several associations that were opposite to those observed for luminal A, including increased risk for parity and younger age at first term full-term pregnancy. Longer duration breastfeeding, increasing number of children breastfed, and increasing number of months breastfeeding per child were each associated with reduced risk of basal-like breast cancer, but not luminal A. Women with multiple live births who did not breastfeed and women who used medications to suppress lactation were at increased risk of basal-like, but not luminal A, breast cancer. Elevated waist-hip ratio was associated with increased risk of luminal A in postmenopausal women, and increased risk of basal-like breast cancer in pre- and postmenopausal women. The prevalence of basal-like breast cancer was highest among premenopausal African-American women, who also showed the highest prevalence of basal-like risk factors. Among younger African-American women, we estimate that up to 68% of basal-like breast cancer could be prevented by promoting breastfeeding and reducing abdominal adiposity. PMID:17578664

  18. Schwann cell basal lamina and nerve regeneration.

    PubMed

    Ide, C; Tohyama, K; Yokota, R; Nitatori, T; Onodera, S

    1983-12-12

    Nerve segments approximately 7 mm long were excised from the predegenerated sciatic nerves of mice, and treated 5 times by repetitive freezing and thawing to kill the Schwann cells. Such treated nerve segments were grafted into the original places so as to be in contact with the proximal stumps. The animals were sacrificed 1, 2, 3, 5, 7 and 10 days after the grafting. The grafts were examined by electron microscopy in the middle part of the graft, i.e. 3-4 mm distal to the proximal end and/or near the proximal and distal ends of the graft. In other instances, the predegenerated nerve segments were minced with a razor blade after repetitive freezing and thawing. Such minced nerves were placed in contact with the proximal stumps of the same nerves. The animals were sacrificed 10 days after the grafting. Within 1-2 days after grafting, the dead Schwann cells had disintegrated into fragments. They were then gradually phagocytosed by macrophages. The basal laminae of Schwann cells, which were not attacked by macrophages, remained as empty tubes (basal lamina scaffolds). In the grafts we examined, no Schwann cells survived the freezing and thawing process. The regenerating axons always grew out through such basal lamina scaffolds, being in contact with the inner surface of the basal lamina (i.e. the side originally facing the Schwann cell plasma membrane). No axons were found outside of the scaffolds. One to two days after grafting, the regenerating axons were not associated with Schwann cells, but after 5-7 days they were accompanied by Schwann cells which were presumed to be migrating along axons from the proximal stumps. Ten days after grafting, proliferating Schwann cells observed in the middle part of the grafts had begun to sort out axons. In the grafts of minced nerves, the fragmented basal laminae of the Schwann cells re-arranged themselves into thicker strands or small aggregations of basal laminae. The regenerating axons, without exception, attached to one side

  19. [Osphradial chemosensory organ as a probable trigger of the cardiac system adaptive reaction to the effect of heavy metals in aquatic mollusks].

    PubMed

    Kamardin, N N; Lubimtsev, V A; Kornienko, E L; Udalova, G P; Kholodkevich, S V; Apostolov, S A

    2015-01-01

    The responses of osphradium in the fresh-water mollusk Viviparus sp. and single osphradial neurons in the pond snail Lymnaea stagnalis to L-glutamine and L-asparagine as well as the changes in these responses under the effect of heavy metals (Cu, Cd) were recorded electrophysiologically. The functional connections of osphradium with the identified neurons of the central pattern generator of respiratory movements and cardiac activity as well as the modification of these connections under the effect of short-term application of HgCl2 solution on the snail's osphradium were investigated. The cardiac rhythm in the mollusk Littorina littorea under the effect of Cu ions was registered non-invasively in long-lasting experiments. The dose-dependent short-term effects of heavy metals changes after osphradium injury were revealed. The implication of osphradium in adaptive reactions of the cardiac system in aquatic mollusks to the environmental heavy metal pollution is suggested. The dependence of cardiac rhythm on the degree of accumulation of copper ions in the mollusk tissues was detected. The results obtained are essential for unraveling neural mechanisms and pathways allowing heavy metals to affect the functional state of hydrobionts, particularly, the cardiac activity frequency characteristics of which are widely used as informative biomarkers to assess physiological condition of aquatic invertebrates. PMID:25859605

  20. Extrastriatal Dopaminergic Circuits of the Basal Ganglia

    PubMed Central

    Rommelfanger, Karen S.; Wichmann, Thomas

    2010-01-01

    The basal ganglia are comprised of the striatum, the external and internal segment of the globus pallidus (GPe and GPi, respectively), the subthalamic nucleus (STN), and the substantia nigra pars compacta and reticulata (SNc and SNr, respectively). Dopamine has long been identified as an important modulator of basal ganglia function in the striatum, and disturbances of striatal dopaminergic transmission have been implicated in diseases such as Parkinson's disease (PD), addiction and attention deficit hyperactivity disorder. However, recent evidence suggests that dopamine may also modulate basal ganglia function at sites outside of the striatum, and that changes in dopaminergic transmission at these sites may contribute to the symptoms of PD and other neuropsychiatric disorders. This review summarizes the current knowledge of the anatomy, functional effects and behavioral consequences of the dopaminergic innervation to the GPe, GPi, STN, and SNr. Further insights into the dopaminergic modulation of basal ganglia function at extrastriatal sites may provide us with opportunities to develop new and more specific strategies for treating disorders of basal ganglia dysfunction. PMID:21103009

  1. Determination of perfluorinated compounds in mollusks by matrix solid-phase dispersion and liquid chromatography-tandem mass spectrometry.

    PubMed

    Villaverde-de-Sáa, Eugenia; Quintana, José Benito; Rodil, Rosario; Ferrero-Refojos, Raúl; Rubí, Elisa; Cela, Rafael

    2012-01-01

    Perfluorinated compounds (PFCs) have been used for over 40 years in different commercial and industrial applications mainly as surfactants and surface protectors and have become an important class of marine emerging pollutants. This study presents the development and validation of a new analytical method to determine the simultaneous presence of eight PFCs in different kinds of mollusks using matrix solid-phase dispersion (MSPD) followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Simplicity of the analytical procedure, low volume of solvent and quantity of sample required, low global price, and integration of extraction and clean-up into a single step, are the most important advantages of the developed methodology. Solvent, solid support (dispersing agent), clean-up sorbent, and their amounts were optimized by means of an experimental design. In the final method, 0.5 g of sample are dispersed with 0.2 g of diatomaceous earth and transferred into a polypropylene syringe containing 4 g of silica as clean-up sorbent. Then, analytes are eluted with 20 mL of acetonitrile. The extract is finally concentrated to a final volume of 0.5 mL in methanol, avoiding extract dryness in order to prevent evaporation losses and injected in the LC-MS/MS. The combination of this MSPD protocol with LC-MS/MS afforded detection limits from 0.05 to 0.3 ng g(-1). Also, a good linearity was established for the eight PFCs in the range from limit of quantification (LOQ) to 500 ng mL(-1) with R(2) > 0.9917. The recovery of the method was studied with three types of spiked mollusk and was in the 64-126% range. Moreover, a mussel sample was spiked and aged for more than 1 month and analyzed by the developed method and a reference method, ion-pair extraction, for comparison, producing both methods statistically equal concentration values. The method was finally applied to the determination of PFCs in different kinds of mollusks revealing concentrations up to 8.3 ng g(-1) for

  2. Epithelial-Mesenchymal Transition Protein Expression in Basal Cell Adenomas and Basal Cell Adenocarcinomas.

    PubMed

    Tesdahl, Brennan A; Wilson, Thomas C; Hoffman, Henry T; Robinson, Robert A

    2016-06-01

    Basal cell adenomas and basal cell adenocarcinomas show marked histomorphologic similarity and are separated microscopically primarily by the invasive characteristics of the adenocarcinomas. We wished to explore potential differences in the expression of epithelial-mesenchymal transition associated proteins in these two tumor types. A tissue microarray was constructed utilizing 29 basal cell adenomas and 16 basal cell adenocarcinomas. Immunohistochemical expression of E-cadherin, beta-catenin, Twist 1 and vimentin were investigated. Both tumors expressed all proteins in a relatively similar manner. Nuclear beta-catenin was essentially limited to the abluminal cell populations in both tumor types. E-cadherin was limited largely to luminal locations but was more prevalent in the adenocarcinomas as compared to the adenomas. Primarily abluminal expression for vimentin was seen, sometimes present in an apical dot-like pattern. Distinct populations of cellular expression of these four markers of epithelial mesenchymal transition were present but were similar in locations in both tumors with no patterns discerned to separate basal cell adenoma from basal cell adenocarcinoma. Given these findings, the mechanisms by which basal cell adenocarcinoma is able to invade while its counterpart, basal cell adenoma can not, may be more complex than in other tumor types. PMID:26442856

  3. Shaping Action Sequences in Basal Ganglia Circuits

    PubMed Central

    Jin, Xin; Costa, Rui M

    2015-01-01

    Many behaviors necessary for organism survival are learned anew and become organized as complex sequences of actions. Recent studies suggest that cortico-basal ganglia circuits are important for chunking isolated movements into precise and robust action sequences that permit the achievement of particular goals. During sequence learning many neurons in the basal ganglia develop sequence-related activity - related to the initiation, execution, and termination of sequences - suggesting that action sequences are processed as action units. Corticostriatal plasticity is critical for the crystallization of action sequences, and for the development of sequence-related neural activity. Furthermore, this sequence-related activity is differentially expressed in direct and indirect basal ganglia pathways. These findings have implications for understanding the symptoms associated with movement and psychiatric disorders. PMID:26189204

  4. Can basal magma oceans generate magnetic fields?

    NASA Astrophysics Data System (ADS)

    Stegman, D. R.; Ziegler, L. B.; Davies, C.

    2015-12-01

    Earth's magnetic field is very old, with recent data now showing the field possibly extended back to 4.1 billion years ago (Tarduno et al., Science, 2015). Yet, based upon our current knowledge there are difficulties in sustained a core dynamo over most of Earth's history. Moreover, recent estimates of thermal and electrical conductivity of liquid iron at core conditions from mineral physics experiments indicate that adiabatic heat flux is approximately 15 TW, nearly 3 times larger than previously thought, exacerbating difficulties for driving a core dynamo by convective core cooling alone throughout Earth history. A long-lived basal magma ocean in the lowermost mantle has been proposed to exist in the early Earth, surviving perhaps into the Archean. While the modern, solid lower mantle is an electromagnetic insulator, electrical conductivities of silicate melts are known to be higher, though as yet they are unconstrained for lowermost mantle conditions. Here we explore the geomagnetic consequences of a basal magma ocean layer for a range of possible electrical conductivities. For the highest electrical conductivities considered, we find a basal magma ocean could be a primary dynamo source region. This would suggest the proposed three magnetic eras observed in paleomagnetic data originate from distinct sources for dynamo generation: from 4.5-2.45 Ga within a basal magma ocean, from 2.25-0.4 Ga within a superadiabatically cooled liquid core, and from 0.4-present within a quasi-adiabatic core that includes a solidifying inner core. We have extended this work by developing a new code, Dynamantle, which is a model with an entropy-based approach, similar to those commonly used in core dynamics models. We present new results using this code to assess the conditions under which basal magma oceans can generate positive ohmic dissipation. This is more generally useful than just considering the early Earth, but also for many silicate exoplanets in which basal magma oceans

  5. Heavy metals in bivalve mollusks collected from Da-Peng Bay Lagoon in south-southwestern Taiwan.

    PubMed

    Shue, Meei-Fang; Chen, Wen-Der; Su, Chia-Chi; Lu, Ming-Chun

    2014-01-01

    In this study, concentrations of several heavy metals (Cu, Pb, Zn, Ni, Cr, and Cd) were measured in Katelysia hiantina, Anomalocardia squamosa, Perna viridis, Anadara antiquata, Paphia undulata, and Sanguinolaria diphos bivalve mollusks from Da-Peng Bay Lagoon near the south-southwestern coast of Taiwan. The metal pollution index (MPI) values were highest and lowest in winter and autumn, respectively. The MPI value in the viscera of P. viridis was higher than in muscles. In all four seasons, Zn concentrations in viscera and muscles of P. viridis were higher than for other metals. The capacities of A. squamosa to accumulate the concentrations of Cu, Ni, and Cr and of A. antiquata to accumulate concentrations of Pb, Zn, and Cd were significant. Analytical results suggested that A. squamosa and A. antiquata may be used as bioindicators for monitoring Cu, Ni, Cr, Pb, Zn, and Cd heavy-metal pollution in Da-Peng Bay Lagoon throughout the year. PMID:24555680

  6. Cloning and characterization of an actin gene of Chlamys farreri and the phylogenetic analysis of mollusk actins

    NASA Astrophysics Data System (ADS)

    Ma, Hongming; Mai, Kangsen; Liufu, Zhiguo; Xu, Wei

    2007-07-01

    An actingene (CfACTI) was cloned by using RT-PCR, 3’ and 5’RACE from hemocytes of the sea scallop Chlamys farreri. The full length of the transcript is 1 535 bp, which contains a long 3’ un-translated region of 436bp and 59bp of a 5’ un-translated sequence. The open reading frame encodes a polypeptide of 376 amino acids. Sequence comparisons indicated that CfACTI is more closely related to vertebrate cytoplasmic actins than muscle types. Phylogenetic analysis showed that molluscan actins could be generally divided into two categories: muscle and cytoplasmic, although both are similar to vertebrate cytoplasmic actins. It was also inferred that different isotypes existed in muscle or cytoplasma in mollusks. The genomic sequence of CfACTI was cloned and sequenced. Only one intron was detected: it was located between codons 42 and 43 and different from vertebrate actin genes.

  7. [Shell Variability of the Terrestrial Mollusk Chondrula tridens (Pulmonata, Enidae) in the Forest-Steppe Zone of the Volga Upland].

    PubMed

    Komarova, E V; Smirnov, D G; Stoiko, T G

    2015-01-01

    Shell variability of the steppe mollusk Chondrula tridens from 18 micropopulations in the forest-steppe zone of the Volga Upland was studied. It was found that larger specimens of Ch. tridens with well-developed teeth inhabit the central and eastern parts of the territory. Specimens in the northwestern part of the upland are characterized by small shells, the highest degree of roundness, and mostly reduced teeth in the mouth. The main factors that determine variability in the size and proportions of shells are the average daily temperatures increasing from the northwest to the south, the reduction in the total precipitation, the decrease in the soil moisture content, and, possibly, the increased content of carbonates in the soil. PMID:26852480

  8. The connectome of the basal ganglia.

    PubMed

    Schmitt, Oliver; Eipert, Peter; Kettlitz, Richard; Leßmann, Felix; Wree, Andreas

    2016-03-01

    The basal ganglia of the laboratory rat consist of a few core regions that are specifically interconnected by efferents and afferents of the central nervous system. In nearly 800 reports of tract-tracing investigations the connectivity of the basal ganglia is documented. The readout of connectivity data and the collation of all the connections of these reports in a database allows to generate a connectome. The collation, curation and analysis of such a huge amount of connectivity data is a great challenge and has not been performed before (Bohland et al. PloS One 4:e7200, 2009) in large connectomics projects based on meta-analysis of tract-tracing studies. Here, the basal ganglia connectome of the rat has been generated and analyzed using the consistent cross-platform and generic framework neuroVIISAS. Several advances of this connectome meta-study have been made: the collation of laterality data, the network-analysis of connectivity strengths and the assignment of regions to a hierarchically organized terminology. The basal ganglia connectome offers differences in contralateral connectivity of motoric regions in contrast to other regions. A modularity analysis of the weighted and directed connectome produced a specific grouping of regions. This result indicates a correlation of structural and functional subsystems. As a new finding, significant reciprocal connections of specific network motifs in this connectome were detected. All three principal basal ganglia pathways (direct, indirect, hyperdirect) could be determined in the connectome. By identifying these pathways it was found that there exist many further equivalent pathways possessing the same length and mean connectivity weight as the principal pathways. Based on the connectome data it is unknown why an excitation pattern may prefer principal rather than other equivalent pathways. In addition to these new findings the local graph-theoretical features of regions of the connectome have been determined. By

  9. 6-Bromohypaphorine from Marine Nudibranch Mollusk Hermissenda crassicornis is an Agonist of Human α7 Nicotinic Acetylcholine Receptor

    PubMed Central

    Kasheverov, Igor E.; Shelukhina, Irina V.; Kudryavtsev, Denis S.; Makarieva, Tatyana N.; Spirova, Ekaterina N.; Guzii, Alla G.; Stonik, Valentin A.; Tsetlin, Victor I.

    2015-01-01

    6-Bromohypaphorine (6-BHP) has been isolated from the marine sponges Pachymatisma johnstoni, Aplysina sp., and the tunicate Aplidium conicum, but data on its biological activity were not available. For the nudibranch mollusk Hermissenda crassicornis no endogenous compounds were known, and here we describe the isolation of 6-BHP from this mollusk and its effects on different nicotinic acetylcholine receptors (nAChR). Two-electrode voltage-clamp experiments on the chimeric α7 nAChR (built of chicken α7 ligand-binding and glycine receptor transmembrane domains) or on rat α4β2 nAChR expressed in Xenopus oocytes revealed no action of 6-BHP. However, in radioligand analysis, 6-BHP competed with radioiodinated α-bungarotoxin for binding to human α7 nAChR expressed in GH4C1 cells (IC50 23 ± 1 μM), but showed no competition on muscle-type nAChR from Torpedo californica. In Ca2+-imaging experiments on the human α7 nAChR expressed in the Neuro2a cells, 6-BHP in the presence of PNU120596 behaved as an agonist (EC50 ~80 μM). To the best of our knowledge, 6-BHP is the first low-molecular weight compound from marine source which is an agonist of the nAChR subtype. This may have physiological importance because H. crassicornis, with its simple and tractable nervous system, is a convenient model system for studying the learning and memory processes. PMID:25775422

  10. 6-bromohypaphorine from marine nudibranch mollusk Hermissenda crassicornis is an agonist of human α7 nicotinic acetylcholine receptor.

    PubMed

    Kasheverov, Igor E; Shelukhina, Irina V; Kudryavtsev, Denis S; Makarieva, Tatyana N; Spirova, Ekaterina N; Guzii, Alla G; Stonik, Valentin A; Tsetlin, Victor I

    2015-03-01

    6-Bromohypaphorine (6-BHP) has been isolated from the marine sponges Pachymatisma johnstoni, Aplysina sp., and the tunicate Aplidium conicum, but data on its biological activity were not available. For the nudibranch mollusk Hermissenda crassicornis no endogenous compounds were known, and here we describe the isolation of 6-BHP from this mollusk and its effects on different nicotinic acetylcholine receptors (nAChR). Two-electrode voltage-clamp experiments on the chimeric α7 nAChR (built of chicken α7 ligand-binding and glycine receptor transmembrane domains) or on rat α4β2 nAChR expressed in Xenopus oocytes revealed no action of 6-BHP. However, in radioligand analysis, 6-BHP competed with radioiodinated α-bungarotoxin for binding to human α7 nAChR expressed in GH4C1 cells (IC50 23 ± 1 μM), but showed no competition on muscle-type nAChR from Torpedo californica. In Ca2+-imaging experiments on the human α7 nAChR expressed in the Neuro2a cells, 6-BHP in the presence of PNU120596 behaved as an agonist (EC50 ~80 μM). To the best of our knowledge, 6-BHP is the first low-molecular weight compound from marine source which is an agonist of the nAChR subtype. This may have physiological importance because H. crassicornis, with its simple and tractable nervous system, is a convenient model system for studying the learning and memory processes. PMID:25775422

  11. Cm-p5: an antifungal hydrophilic peptide derived from the coastal mollusk Cenchritis muricatus (Gastropoda: Littorinidae)

    PubMed Central

    López-Abarrategui, Carlos; McBeth, Christine; Mandal, Santi M.; Sun, Zhenyu J.; Heffron, Gregory; Alba-Menéndez, Annia; Migliolo, Ludovico; Reyes-Acosta, Osvaldo; García-Villarino, Mónica; Nolasco, Diego O.; Falcão, Rosana; Cherobim, Mariana D.; Dias, Simoni C.; Brandt, Wolfgang; Wessjohann, Ludger; Starnbach, Michael; Franco, Octavio L.; Otero-González, Anselmo J.

    2015-01-01

    Antimicrobial peptides form part of the first line of defense against pathogens for many organisms. Current treatments for fungal infections are limited by drug toxicity and pathogen resistance. Cm-p5 (SRSELIVHQRLF), a peptide derived from the marine mollusk Cenchritis muricatus peptide Cm-p1, has a significantly increased fungistatic activity against pathogenic Candida albicans (minimal inhibitory concentration, 10 µg/ml; EC50, 1.146 µg/ml) while exhibiting low toxic effects against a cultured mammalian cell line. Cm-p5 as characterized by circular dichroism and nuclear magnetic resonance revealed an α-helical structure in membrane-mimetic conditions and a tendency to random coil folding in aqueous solutions. Additional studies modeling Cm-p5 binding to a phosphatidylserine bilayer in silico and isothermal titration calorimetry using lipid monophases demonstrated that Cm-p5 has a high affinity for the phospholipids of fungal membranes (phosphatidylserine and phosphatidylethanolamine), only moderate interactions with a mammalian membrane phospholipid, low interaction with ergosterol, and no interaction with chitin. Adhesion of Cm-p5 to living C. albicans cells was confirmed by fluorescence microscopy with FITC-labeled peptide. In a systemic candidiasis model in mice, intraperitoneal administration of Cm-p5 was unable to control the fungal kidney burden, although its low amphiphaticity could be modified to generate new derivatives with improved fungicidal activity and stability.—López-Abarrategui, C., McBeth, C., Mandal, S. M., Sun, Z. J., Heffron, G., Alba-Menéndez, A., Migliolo, L., Reyes-Acosta, O., García-Villarino, M., Nolasco, D. O., Falcão, R., Cherobim, M. D., Dias, S. C., Brandt, W., Wessjohann, L., Starnbach, M., Franco, O. L., Otero-González, A. J. Cm-p5: an antifungal hydrophilic peptide derived from the coastal mollusk Cenchritis muricatus (Gastropoda: Littorinidae). PMID:25921828

  12. Repeated sampling of individual bivalve mollusks I: intraindividual variability and consequences for haemolymph constituents of the Manila clam, Ruditapes philippinarum.

    PubMed

    Ford, Susan E; Paillard, Christine

    2007-08-01

    Components of the haemolymph are understood to constitute the internal defense system of bivalve mollusks and their levels are often considered to be indicators of "health"; however, relatively little proof exists of the role that these elements play in the success or failure of defense against a pathogen. A change associated with infection may be the consequence of disease rather than a measure of the capacity to respond effectively to a pathogen. One way to assess whether haemocyte or serum-component concentrations are related to resistance to microbial infection is to sample individuals over time, both before and after they are experimentally or naturally infected. But sampling itself may alter the parameter being assessed. In addition, interindividual variation is large and the degree of intraindividual variation over time is largely unknown. To evaluate intra- vs interindividual variability measured over time and to assess the effects of repeated sampling, we subjected Manila clams, Ruditapes philippinarum, to multiple haemolymph samplings during both field and laboratory experiments, and measured four parameters: haemocyte density, protein concentration, and the activities of leucine amino peptidase and DOPA-oxidase. A repeated-measures ANOVA indicated that individuals with high or low levels at one sampling, tended to have high or low levels, respectively, at the other sampling times. Furthermore, the index of individuality, which is the ratio of intra- to interindividual variability, for these four parameters was comparable to that for human serum components. Repeated sampling had no measured effect on field-deployed clams, which were sampled at intervals of 1-3 months, but significantly depressed values in laboratory-held clams sampled at 1-month intervals. Results demonstrated relative intraindividual constancy in the measured variables and suggested that minimizing sample frequency and volume, and maintaining animals in a comparatively natural

  13. Reconstructing past upwelling intensity and the seasonal dynamics of primary productivity along the Peruvian coastline from mollusk shell stable isotopes

    NASA Astrophysics Data System (ADS)

    Sadler, James; Carré, Matthieu; Azzoug, Moufok; Schauer, Andrew J.; Ledesma, Jesus; Cardenas, Fredy; Chase, Brian M.; Bentaleb, Ilhem; Muller, Serge D.; Mandeng, Magloire; Rohling, Eelco J.; Sachs, Julian P.

    2012-01-01

    We present here a potential new method to evaluate past variations of the mean intensity of Peruvian coastal upwelling and of the seasonal timing of phytoplankton blooms. This method uses a combination of the monthly carbon and oxygen isotopic signals preserved in fossil mollusk shells, and a series of corrections to extract the variations of the dissolved inorganic carbon (DIC) δ13C. Based on the analysis of five shell samples (85 shells in total) from the southern Peruvian coast, we suggest that the mean coastal upwelling intensity can be determined from a linear relationship between average values of corrected shell δ13C and δ18O. This new potential proxy would bring additional independent information valuable to interpret paleoproductivity changes reconstructed from marine sediment of the nearby continental shelf. Results obtained on fossil samples from the middle Holocene show an increase in upwelling intensity during this period associated to a spatial reorganization of upwelling centers along the South Peruvian coast. At the seasonal scale, corrected shell δ13C enrichment indicates a phytoplankton bloom. Seasonal timing of phytoplankton blooms can be estimated by the lag with the annual temperature cycle reproduced by shell δ18O monthly variations. The results obtained with two modern shell samples indicate phytoplankton blooms occurring during summer and fall, consistently with in situ productivity observations. Our method relies on revisited assumptions about the influence of temperature and metabolism in mollusk shell δ13C. We further discussed the validity of these assumptions and the potential implications for the interpretation of similar data sets.

  14. Basal ganglia germinoma with progressive cerebral hemiatrophy.

    PubMed

    Liu, E; Robertson, R L; du Plessis, A; Pomeroy, S L

    1999-04-01

    The authors describe a 7-year-old Chinese-American female with a germinoma of the basal ganglia who presented with progressive hemiparesis and cerebral hemiatrophy. The additional finding of markedly elevated antiphospholipid antibodies suggests the possibility of an autoimmune pathogenesis for the progressive cerebral atrophy, as well as the later development of cognitive decline, tics, and obsessive-compulsive behaviors. PMID:10328283

  15. Basal Ganglia Germinoma in an Adult.

    PubMed

    Vialatte de Pémille, Clément; Bielle, Franck; Mokhtari, Karima; Kerboua, Esma; Alapetite, Claire; Idbaih, Ahmed

    2016-08-01

    Intracranial germinoma is a rare primary brain cancer, usually located within the midline and mainly affecting Asian pediatric patients. Interestingly, we report here the peculiar case of a young North-African adult patient suffering from a basal ganglia germinoma without the classical ipsilateral cerebral hemiatrophy associated with this location. PMID:27241091

  16. Reward functions of the basal ganglia.

    PubMed

    Schultz, Wolfram

    2016-07-01

    Besides their fundamental movement function evidenced by Parkinsonian deficits, the basal ganglia are involved in processing closely linked non-motor, cognitive and reward information. This review describes the reward functions of three brain structures that are major components of the basal ganglia or are closely associated with the basal ganglia, namely midbrain dopamine neurons, pedunculopontine nucleus, and striatum (caudate nucleus, putamen, nucleus accumbens). Rewards are involved in learning (positive reinforcement), approach behavior, economic choices and positive emotions. The response of dopamine neurons to rewards consists of an early detection component and a subsequent reward component that reflects a prediction error in economic utility, but is unrelated to movement. Dopamine activations to non-rewarded or aversive stimuli reflect physical impact, but not punishment. Neurons in pedunculopontine nucleus project their axons to dopamine neurons and process sensory stimuli, movements and rewards and reward-predicting stimuli without coding outright reward prediction errors. Neurons in striatum, besides their pronounced movement relationships, process rewards irrespective of sensory and motor aspects, integrate reward information into movement activity, code the reward value of individual actions, change their reward-related activity during learning, and code own reward in social situations depending on whose action produces the reward. These data demonstrate a variety of well-characterized reward processes in specific basal ganglia nuclei consistent with an important function in non-motor aspects of motivated behavior. PMID:26838982

  17. How Basal Reading Texts Affect Children's Writing.

    ERIC Educational Resources Information Center

    Eckhoff, Barbara L.

    A study investigated how children's writing reflects the syntactic complexity, style, and format of their basal readers. Subjects were 116 students drawn from 10 second, third, and fourth grade classrooms in two different schools located near Boston, Massachusetts. A matched group design was used, and students using a form of the "Ginn" basal…

  18. TEMPORAL VARIABILITY IN BASAL ISOPRENE EMISSION FACTOR

    EPA Science Inventory

    Seasonal variability in basal isoprene emission factor (micrograms C /g hr or nmol/ m2 sec, leaf temperature at 30 degrees C and photosynthetically active radiation (PAR) at 1000 micromol/ m2 sec) was studied during the 1998 growing season at Duke Forest in the North Carolina Pie...

  19. Enhancing Basal Vocabulary Instruction in Kindergarten

    ERIC Educational Resources Information Center

    Lenfest, Ashleigh; Reed, Deborah K.

    2015-01-01

    To enhance the basal vocabulary instruction for kindergarten students at risk for reading difficulties, lessons provided in typical curricular materials can be supplemented with instructional elements derived from research. This article addresses how teachers can add 15 minutes of higher order instructional activities to daily reading lessons to…

  20. Functional anatomy of thalamus and basal ganglia.

    PubMed

    Herrero, María-Trinidad; Barcia, Carlos; Navarro, Juana Mari

    2002-08-01

    THALAMUS: The human thalamus is a nuclear complex located in the diencephalon and comprising of four parts (the hypothalamus, the epythalamus, the ventral thalamus, and the dorsal thalamus). The thalamus is a relay centre subserving both sensory and motor mechanisms. Thalamic nuclei (50-60 nuclei) project to one or a few well-defined cortical areas. Multiple cortical areas receive afferents from a single thalamic nucleus and send back information to different thalamic nuclei. The corticofugal projection provides positive feedback to the "correct" input, while at the same time suppressing irrelevant information. Topographical organisation of the thalamic afferents and efferents is contralateral, and the lateralisation of the thalamic functions affects both sensory and motoric aspects. Symptoms of lesions located in the thalamus are closely related to the function of the areas involved. An infarction or haemorrhage thalamic lesion can develop somatosensory disturbances and/or central pain in the opposite hemibody, analgesic or purely algesic thalamic syndrome characterised by contralateral anaesthesia (or hypaesthesia), contralateral weakness, ataxia and, often, persistent spontaneous pain. BASAL GANGLIA: Basal ganglia form a major centre in the complex extrapyramidal motor system, as opposed to the pyramidal motor system (corticobulbar and corticospinal pathways). Basal ganglia are involved in many neuronal pathways having emotional, motivational, associative and cognitive functions as well. The striatum (caudate nucleus, putamen and nucleus accumbens) receive inputs from all cortical areas and, throughout the thalamus, project principally to frontal lobe areas (prefrontal, premotor and supplementary motor areas) which are concerned with motor planning. These circuits: (i) have an important regulatory influence on cortex, providing information for both automatic and voluntary motor responses to the pyramidal system; (ii) play a role in predicting future events

  1. Learning Reward Uncertainty in the Basal Ganglia.

    PubMed

    Mikhael, John G; Bogacz, Rafal

    2016-09-01

    Learning the reliability of different sources of rewards is critical for making optimal choices. However, despite the existence of detailed theory describing how the expected reward is learned in the basal ganglia, it is not known how reward uncertainty is estimated in these circuits. This paper presents a class of models that encode both the mean reward and the spread of the rewards, the former in the difference between the synaptic weights of D1 and D2 neurons, and the latter in their sum. In the models, the tendency to seek (or avoid) options with variable reward can be controlled by increasing (or decreasing) the tonic level of dopamine. The models are consistent with the physiology of and synaptic plasticity in the basal ganglia, they explain the effects of dopaminergic manipulations on choices involving risks, and they make multiple experimental predictions. PMID:27589489

  2. What do the basal ganglia do?

    PubMed

    Brown, P; Marsden, C D

    1998-06-13

    We propose that the basal ganglia support a basic attentional mechanism operating to bind input to output in the executive forebrain. Such focused attention provides the automatic link between voluntary effort, sensory input, and the calling up and operation of a sequence of motor programmes or thoughts. The physiological basis for this attentional mechanism may lie in the tendency of distributed, but related, cortical activities to synchronise in the gamma (30 to 50 Hz) band, as occurs in the visual cortex. Coherent and synchronised elements are more effective when convergence occurs during successive stages of processing, and in this way may come together to give the one gestalt or action. We suggest that the basal ganglia have a major role in facilitating this aspect of neuronal processing in the forebrain, and that loss of this function contributes to parkinsonism and abulia. PMID:9635969

  3. RFamide peptides in agnathans and basal chordates.

    PubMed

    Osugi, Tomohiro; Son, You Lee; Ubuka, Takayoshi; Satake, Honoo; Tsutsui, Kazuyoshi

    2016-02-01

    Since a peptide with a C-terminal Arg-Phe-NH2 (RFamide peptide) was first identified in the ganglia of the venus clam in 1977, RFamide peptides have been found in the nervous system of both invertebrates and vertebrates. In vertebrates, the RFamide peptide family includes gonadotropin-inhibitory hormone (GnIH), neuropeptide FF (NPFF), prolactin-releasing peptide (PrRP), pyroglutamylated RFamide peptide/26RFamide peptide (QRFP/26RFa), and kisspeptins (kiss1 and kiss2). They are involved in important functions such as the release of hormones, regulation of sexual or social behavior, pain transmission, reproduction, and feeding. In contrast to tetrapods and jawed fish, the information available on RFamide peptides in agnathans and basal chordates is limited, thus preventing further insights into the evolution of RFamide peptides in vertebrates. In this review, we focus on the previous research and recent advances in the studies on RFamide peptides in agnathans and basal chordates. In agnathans, the genes encoding GnIH, NPFF, and PrRP precursors and the mature peptides have been identified in lamprey (Petromyzon marinus) and hagfish (Paramyxine atami). Putative kiss1 and kiss2 genes have also been found in the genome database of lamprey. In basal chordates, namely, in amphioxus (Branchiostoma japonicum), a common ancestral form of GnIH and NPFF genes and their mature peptides, as well as the ortholog of the QRFP gene have been identified. The studies revealed that the number of orthologs of vertebrate RFamide peptides present in agnathans and basal chordates is greater than expected, suggesting that the vertebrate RFamide peptides might have emerged and expanded at an early stage of chordate evolution. PMID:26130238

  4. Active decorrelation in the basal ganglia.

    PubMed

    Wilson, C J

    2013-10-10

    The cytoarchitecturally-homogeneous appearance of the globus pallidus, subthalamic nucleus and substantia nigra has long been said to imply a high degree of afferent convergence and sharing of inputs by nearby neurons. Moreover, axon collaterals of neurons in the external segment of the globus pallidus and the substantia nigra pars reticulata arborize locally and make inhibitory synapses on other cells of the same type. These features suggest that the connectivity of the basal ganglia may impose spike-time correlations among the cells, and it has been puzzling that experimental studies have failed to demonstrate such correlations. One possible solution arises from studies of firing patterns in basal ganglia cells, which reveal that they are nearly all pacemaker cells. Their high rate of firing does not depend on synaptic excitation, but they fire irregularly because a dense barrage of synaptic inputs normally perturbs the timing of their autonomous activity. Theoretical and computational studies show that the responses of repetitively-firing neurons to shared input or mutual synaptic coupling often defy classical intuitions about temporal synaptic integration. The patterns of spike-timing among such neurons depend on the ionic mechanism of pacemaking, the level of background uncorrelated cellular and synaptic noise, and the firing rates of the neurons, as well as the properties of their synaptic connections. Application of these concepts to the basal ganglia circuitry suggests that the connectivity and physiology of these nuclei may be configured to prevent the establishment of permanent spike-timing relationships between neurons. The development of highly synchronous oscillatory patterns of activity in Parkinson's disease may result from the loss of pacemaking by some basal ganglia neurons, and accompanying breakdown of the mechanisms responsible for active decorrelation. PMID:23892007

  5. Basal hydraulic conditions of Ice Stream B

    NASA Technical Reports Server (NTRS)

    Engelhardt, Hermann; Kamb, Barclay

    1993-01-01

    Fifteen boreholes have been drilled to the base of Ice Stream B in the vicinity of UpB Camp. The boreholes are spread over an area of about 500 x 1000 m. Several till cores were retrieved from the bottom of the 1000-m-deep holes. Laboratory tests using a simple shear box revealed a yield strength of basal till of 2 kPa. This agrees well with in-situ measurements using a shear vane. Since the average basal shear stress of Ice Stream B with a surface slope of 0.1 degree is about 20 kPa, the ice stream cannot be supported by till that weak. Additional support for this conclusion comes from the basal water pressure that has been measured in all boreholes as soon as the hot water drill reached bottom. In several boreholes, the water pressure has been continuously monitored; in two of them, over several years. The water pressure varies but stays within 1 bar of flotation where ice overburden pressure and water pressure are equal. The ratio of water and overburden pressure lies between 0.986 and 1.002. This is an extremely high value as compared to other fast-moving ice masses; e.g., Variegated Glacier in surge has a ratio of 0.8, and Columbia Glacier - a fast-moving tidewater glacier - has a ratio of 0.9. It implies that water flow under the glacier occurs in a thin film and not in conduits that would drain away water too rapidly. It also implies that basal sliding must be very effective. Water flow under the glacier was measured in a salt-injection experiment where a salt pulse was released at the bottom of a borehole while 60 m down-glacier, the electrical resistance was measured between two other boreholes. A flow velocity of 7 mm/s was obtained.

  6. Basal cell nevus syndrome - close-up of palm (image)

    MedlinePlus

    ... skeletal abnormalities. Skin manifestations include pits in the palms and soles, and numerous basal cell carcinomas. This ... close-up of the pits found in the palm of an individual with basal cell nevus syndrome.

  7. Iodothyronine deiodinase gene analysis of the Pacific oyster Crassostrea gigas reveals possible conservation of thyroid hormone feedback regulation mechanism in mollusks

    NASA Astrophysics Data System (ADS)

    Huang, Wen; Xu, Fei; Qu, Tao; Li, Li; Que, Huayong; Zhang, Guofan

    2015-07-01

    Iodothyronine deiodinase catalyzes the initiation and termination of thyroid hormones (THs) effects, and plays a central role in the regulation of thyroid hormone level in vertebrates. In non-chordate invertebrates, only one deiodinase has been identified in the scallop Chlamys farreri. Here, two deiodinases were cloned in the Pacific oyster Crassostrea gigas ( CgDx and CgDy). The characteristic in-frame TGA codons and selenocysteine insertion sequence elements in the oyster deiodinase cDNAs supported the activity of them. Furthermore, seven orthologs of deiodinases were found by a tblastn search in the mollusk Lottia gigantea and the annelid Capitella teleta. A phylogenetic analysis revealed that the deiodinase gene originated from an common ancestor and a clade-specific gene duplication occurred independently during the differentiation of the mollusk, annelid, and vertebrate lineages. The distinct spatiotemporal expression patterns implied functional divergence of the two deiodinases. The expression of CgDx and CgDy was influenced by L-thyroxine T4, and putative thyroid hormone responsive elements were found in their promoters, which suggested that the oyster deiodinases were feedback regulated by TH. Epinephrine stimulated the expression level of CgDx and CgDy, suggesting an interaction effect between different hormones. This study provides the first evidence for the existence of a conserved TH feedback regulation mechanism in mollusks, providing insights into TH evolution.

  8. Evaluation of microwave and ultrasound extraction procedures for arsenic speciation in bivalve mollusks by liquid chromatography-inductively coupled plasma-mass spectrometry

    NASA Astrophysics Data System (ADS)

    Santos, Clarissa M. M.; Nunes, Matheus A. G.; Barbosa, Isa S.; Santos, Gabriel L.; Peso-Aguiar, Marlene C.; Korn, Maria G. A.; Flores, Erico M. M.; Dressler, Valderi L.

    2013-08-01

    Liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS) was used for arsenic speciation analysis in tissues of bivalve mollusks (Anomalocardia brasiliana sp. and Macoma constricta sp.). Microwave and ultrasound radiation, combined with different extraction conditions (solvent, sample amount, time, and temperature), were evaluated for As-species extraction from the mollusks' tissues. Accuracy, extraction efficiency, and the stability of As species were evaluated by analyzing certified reference materials (DORM-2, dogfish muscle; BCR-627, tuna fish tissue; and SRM 1566b, oyster tissue) and analyte recovery tests. The best conditions were found to be microwave-assisted extraction using 200 mg of samples and water at 80 °C for 6 min. The agreement of As-species concentration in samples ranged from 97% to 102%. Arsenobetaine (AsB) was the main species present in bivalve mollusk tissues, while monomethylarsonic acid (MMA) and arsenate (As(V)) were below the limit of quantification (0.001 and 0.003 μg g- 1, respectively). Two unidentified As species also were detected and quantified. The sum of the As-species concentration was in agreement (90 to 104%), with the total As content determined by ICP-MS after sample digestion.

  9. Activation of transcription and retrotransposition of a novel retroelement, Steamer, in neoplastic hemocytes of the mollusk Mya arenaria

    PubMed Central

    Arriagada, Gloria; Metzger, Michael J.; Muttray, Annette F.; Sherry, James; Reinisch, Carol; Street, Craig; Lipkin, W. Ian; Goff, Stephen P.

    2014-01-01

    Bivalve mollusks of the North Atlantic, most prominently the soft shell clam Mya arenaria, are afflicted with an epidemic transmissible disease of the circulatory system closely resembling leukemia. The disease is characterized by a dramatic expansion of blast-like cells in the hemolymph with high mitotic index. Examination of hemolymph of diseased clams revealed high levels of reverse transcriptase activity, the hallmark of retroviruses and retroelements. By deep sequencing of RNAs from hemolymph, we identified transcripts of a novel retroelement, here named Steamer. The DNA of the element is marked by long terminal repeats and encodes a single large protein with similarity to mammalian retroviral Gag-Pol proteins. Steamer mRNA levels were specifically elevated in diseased hemocytes, and high expression was correlated with disease status. DNA copy number per genome was present at enormously high levels in diseased hemocytes, indicative of extensive reverse transcription and retrotransposition. Steamer activation in M. arenaria is an example of a catastrophic induction of genetic instability that may initiate or advance the course of leukemia. PMID:25201971

  10. Spatial distribution of Biomphalaria mollusks at São Francisco River Basin, Minas Gerais, Brazil, using geostatistical procedures.

    PubMed

    Guimarães, Ricardo J P S; Freitas, Corina C; Dutra, Luciano V; Felgueiras, Carlos A; Moura, Ana C M; Amaral, Ronaldo S; Drummond, Sandra C; Scholte, Ronaldo G C; Oliveira, Guilherme; Carvalho, Omar S

    2009-03-01

    Geostatistics is used in this work to make inferences about the presence of the species of Biomphalaria (B. glabrata, B. tenagophila and/or B. straminea), intermediate hosts of Schistosoma mansoni, at the São Francisco River Basin, in Minas Gerais, Brazil. One of these geostatistical procedures, known as indicator kriging, allows the classification of categorical data, in areas where the data are not available, using a punctual sample set. The result is a map of species and risk area definition. More than a single map of the categorical attribute, the procedure also permits the association of uncertainties of the stochastic model, which can be used to qualify the inferences. In order to validate the estimated data of the risk map, a fieldwork in five municipalities was carried out. The obtained results showed that indicator kriging is a rather robust tool since it presented a very good agreement with the field findings. The obtained risk map can be thought as an auxiliary tool to formulate proper public health strategies, and to guide other fieldwork, considering the places with higher occurrence probability of the most important snail species. Also, the risk map will enable better resource distribution and adequate policies for the mollusk control. This methodology will be applied to other river basins to generate a predictive map for Biomphalaria species distribution for the entire state of Minas Gerais. PMID:19046937

  11. Cm-p5: an antifungal hydrophilic peptide derived from the coastal mollusk Cenchritis muricatus (Gastropoda: Littorinidae).

    PubMed

    López-Abarrategui, Carlos; McBeth, Christine; Mandal, Santi M; Sun, Zhenyu J; Heffron, Gregory; Alba-Menéndez, Annia; Migliolo, Ludovico; Reyes-Acosta, Osvaldo; García-Villarino, Mónica; Nolasco, Diego O; Falcão, Rosana; Cherobim, Mariana D; Dias, Simoni C; Brandt, Wolfgang; Wessjohann, Ludger; Starnbach, Michael; Franco, Octavio L; Otero-González, Anselmo J

    2015-08-01

    Antimicrobial peptides form part of the first line of defense against pathogens for many organisms. Current treatments for fungal infections are limited by drug toxicity and pathogen resistance. Cm-p5 (SRSELIVHQRLF), a peptide derived from the marine mollusk Cenchritis muricatus peptide Cm-p1, has a significantly increased fungistatic activity against pathogenic Candida albicans (minimal inhibitory concentration, 10 µg/ml; EC50, 1.146 µg/ml) while exhibiting low toxic effects against a cultured mammalian cell line. Cm-p5 as characterized by circular dichroism and nuclear magnetic resonance revealed an α-helical structure in membrane-mimetic conditions and a tendency to random coil folding in aqueous solutions. Additional studies modeling Cm-p5 binding to a phosphatidylserine bilayer in silico and isothermal titration calorimetry using lipid monophases demonstrated that Cm-p5 has a high affinity for the phospholipids of fungal membranes (phosphatidylserine and phosphatidylethanolamine), only moderate interactions with a mammalian membrane phospholipid, low interaction with ergosterol, and no interaction with chitin. Adhesion of Cm-p5 to living C. albicans cells was confirmed by fluorescence microscopy with FITC-labeled peptide. In a systemic candidiasis model in mice, intraperitoneal administration of Cm-p5 was unable to control the fungal kidney burden, although its low amphiphaticity could be modified to generate new derivatives with improved fungicidal activity and stability. PMID:25921828

  12. From Mollusks to Medicine: A Venomics Approach for the Discovery and Characterization of Therapeutics from Terebridae Peptide Toxins.

    PubMed

    Verdes, Aida; Anand, Prachi; Gorson, Juliette; Jannetti, Stephen; Kelly, Patrick; Leffler, Abba; Simpson, Danny; Ramrattan, Girish; Holford, Mandë

    2016-01-01

    Animal venoms comprise a diversity of peptide toxins that manipulate molecular targets such as ion channels and receptors, making venom peptides attractive candidates for the development of therapeutics to benefit human health. However, identifying bioactive venom peptides remains a significant challenge. In this review we describe our particular venomics strategy for the discovery, characterization, and optimization of Terebridae venom peptides, teretoxins. Our strategy reflects the scientific path from mollusks to medicine in an integrative sequential approach with the following steps: (1) delimitation of venomous Terebridae lineages through taxonomic and phylogenetic analyses; (2) identification and classification of putative teretoxins through omics methodologies, including genomics, transcriptomics, and proteomics; (3) chemical and recombinant synthesis of promising peptide toxins; (4) structural characterization through experimental and computational methods; (5) determination of teretoxin bioactivity and molecular function through biological assays and computational modeling; (6) optimization of peptide toxin affinity and selectivity to molecular target; and (7) development of strategies for effective delivery of venom peptide therapeutics. While our research focuses on terebrids, the venomics approach outlined here can be applied to the discovery and characterization of peptide toxins from any venomous taxa. PMID:27104567

  13. From Mollusks to Medicine: A Venomics Approach for the Discovery and Characterization of Therapeutics from Terebridae Peptide Toxins

    PubMed Central

    Verdes, Aida; Anand, Prachi; Gorson, Juliette; Jannetti, Stephen; Kelly, Patrick; Leffler, Abba; Simpson, Danny; Ramrattan, Girish; Holford, Mandë

    2016-01-01

    Animal venoms comprise a diversity of peptide toxins that manipulate molecular targets such as ion channels and receptors, making venom peptides attractive candidates for the development of therapeutics to benefit human health. However, identifying bioactive venom peptides remains a significant challenge. In this review we describe our particular venomics strategy for the discovery, characterization, and optimization of Terebridae venom peptides, teretoxins. Our strategy reflects the scientific path from mollusks to medicine in an integrative sequential approach with the following steps: (1) delimitation of venomous Terebridae lineages through taxonomic and phylogenetic analyses; (2) identification and classification of putative teretoxins through omics methodologies, including genomics, transcriptomics, and proteomics; (3) chemical and recombinant synthesis of promising peptide toxins; (4) structural characterization through experimental and computational methods; (5) determination of teretoxin bioactivity and molecular function through biological assays and computational modeling; (6) optimization of peptide toxin affinity and selectivity to molecular target; and (7) development of strategies for effective delivery of venom peptide therapeutics. While our research focuses on terebrids, the venomics approach outlined here can be applied to the discovery and characterization of peptide toxins from any venomous taxa. PMID:27104567

  14. Distribution of aliphatic compounds in bivalve mollusks from Galicia after the Prestige oil spill: spatial and temporal trends.

    PubMed

    Carro, N; Cobas, J; Maneiro, J

    2006-03-01

    The content and distribution of n-alkane (C8-C35) and isoprenoid (pristane and phytane) hydrocarbons were investigated in two species of bivalve mollusk, mussel (Mytilus galloprovincialis) and cockle (Cerastoderma edule), collected at different points of the Galicia littoral zone during the period from December 2002 to February 2003 (after the Prestige oil spill). Samples were analyzed by high-resolution gas chromatography equipped with a flame ionization detector. The highest levels were found in mussels and cockles coming from two estuarine bays, Rías de Arousa and Vigo. Hydrocarbons with carbon chain length > 30 were detected and determined in all samples. The abundance of these hydrocarbons in biota could be interpreted with regard to the feeding and living habits. Chemometric techniques have been employed to analyze data and determine the potential source of hydrocarbon contamination. Differences between mussels and cockles were observed in relation to aliphatic content. According to the data analysis, the main source of hydrocarbon contamination of investigated samples seems to be more related to the intense traffic of vessels in these estuarine bays than to the Prestige oil spill. PMID:16253223

  15. A continuous multi-millennial record of surficial bivalve mollusk shells from the São Paulo Bight, Brazilian shelf

    NASA Astrophysics Data System (ADS)

    Dexter, Troy A.; Kaufman, Darrell S.; Krause, Richard A.; Barbour Wood, Susan L.; Simões, Marcello G.; Huntley, John Warren; Yanes, Yurena; Romanek, Christopher S.; Kowalewski, Michał

    2014-03-01

    To evaluate the potential of using surficial shell accumulations for paleoenvironmental studies, an extensive time series of individually dated specimens of the marine infaunal bivalve mollusk Semele casali was assembled using amino acid racemization (AAR) ratios (n = 270) calibrated against radiocarbon ages (n = 32). The shells were collected from surface sediments at multiple sites across a sediment-starved shelf in the shallow sub-tropical São Paulo Bight (São Paulo State, Brazil). The resulting 14C-calibrated AAR time series, one of the largest AAR datasets compiled to date, ranges from modern to 10,307 cal yr BP, is right skewed, and represents a remarkably complete time series: the completeness of the Holocene record is 66% at 250-yr binning resolution and 81% at 500-yr binning resolution. Extensive time-averaging is observed for all sites across the sampled bathymetric range indicating long water depth-invariant survival of carbonate shells at the sediment surface with low net sedimentation rates. Benthic organisms collected from active depositional surfaces can provide multi-millennial time series of biomineral records and serve as a source of geochemical proxy data for reconstructing environmental and climatic trends throughout the Holocene at centennial resolution. Surface sediments can contain time-rich shell accumulations that record the entire Holocene, not just the present.

  16. Radiocarbon content of pre-bomb marine mollusks and variations in the 14C Reservoir age for coastal areas of the Barents and Kara Seas, Russia

    NASA Astrophysics Data System (ADS)

    Forman, Steven L.; Polyak, Leonid

    Fourteen mollusks, collected alive between 1900 and 1945 from the Russian Barents and Kara seas, were analyzed by AMS 14C dating to evaluate variations in the 14C marine reservoir for arctic coastal sites, which is important for correcting ages in paleoenvironmental time-series and advancing understanding of the exchange of carbon. The 14C ages on the mollusks reveal a range of marine reservoir values (R(t)) from 159 14C yr to 764 14C yr. The oldest R(t) values of 764 to 620 14C yr are for the bivalve Portlandia arctica, which often inhabit cold and low salinity waters and muddy substrates. The depleted 14C content for this bivalve reflects possibly the incorporation of old carbon from freshwater inputs and/or the consumption of old organic matter from the underlying sediments and pore waters. Other mollusks with sessile habitats and pelagic food sources gave significantly lower R(t) values between 159 and 344 14C yr. The youngest R(t) values indicate enrichment in 14C and may partially reflect enhanced transfer of 14C-enriched CO2 from the atmosphere to the ocean surface with wind-generated wave agitation. This study underscores that a variety of processes can lead to variable 14C depletion and enrichment of surface waters yielding a ca. 600 year age span for contemporaneous arctic mollusks. There may be added uncertainty in the 14C reservoir correction for deposit-feeder species such as Portlandia sp. and perhaps for certain benthic foraminifera (e.g. Nonion labradoricum) because these taxa often incorporate old organic matter from the substrate. A reservoir correction of ≥700 years may be more appropriate for infaunal, deposit-eater species, particularly in glacier-dominated environments. Mollusks and foraminifera with sessile habits and pelagic food sources should be selected preferentially for 14C dating, because their shells may more closely reflect the 14C content of the global-ocean mixed layer.

  17. Fractionation of a Basal Magma Ocean

    NASA Astrophysics Data System (ADS)

    Laneuville, M.; Hernlund, J. W.; Labrosse, S.

    2014-12-01

    Earth's magnetic field is thought to be sustained by dynamo action in a convecting metallic outer core since at least 3.45 Ga (Tarduno et al., 2010). Convection induces an isentropic temperature gradient that drains 13±3 TW of heat from the core by thermal conduction (de Koker et al., 2012; Pozzo et al., 2012; Gomi et al., 2013), and suggests that Earth's core has cooled by ˜1,000 K or more since Earth's formation (Gomi et al., 2013). However, models of Earth's initial thermal evolution following a giant-impact predict rapid cooling to the mantle melting temperature (e.g., Solomatov, 2007). In order to understand how the core could have retained enough heat to explain the age of the geodynamo, we relax a key assumption of the basal magma ocean model of (Labrosse et al., 2007) to allow for the possibility that the magma is stably stratified. Recent giant impact simulations suggest extensive core-mantle mixing (Saitoh and Makino, 2013), which could have produced such a large stratified magma layer at the core-mantle boundary. In the presence of a stable density gradient, heat transfer through the basal magma ocean occurs through conduction and therefore delays heat loss from the core. Partitioning of iron in the liquid phase upon crystallization changes the density profile and triggers convection in the upper part of the basal magma ocean. Our hypothesis suggests that early core cooling is dominated by the diffusion timescale through the basal magma ocean, and predicts a delayed onset of the geodynamo (i.e, during the late Headean/early Archean). This model can therefore be falsified if the existence of a geomagnetic field can be inferred from magnetization of inclusions in Hadean zircons. N. de Koker et al., Proc. Natl. Acad. Sci. 190, 4070-4073 (2012).H. Gomi et al., Phys. Earth Planet. Inter. 224, 88-103 (2013).S. Labrosse et al., Nature 450, 866-869 (2007).M. Pozzo et al., Nature 485, 355-358 (2012).T. Saitoh and J. Makino. Astrophys. J. 768, 44 (2013).V

  18. Mössbauer spectroscopy of Basal Ganglia

    SciTech Connect

    Miglierini, Marcel; Lančok, Adriana; Kopáni, Martin; Boča, Roman

    2014-10-27

    Chemical states, structural arrangement, and magnetic features of iron deposits in biological tissue of Basal Ganglia are characterized. The methods of SQUID magnetometry and electron microscopy are employed. {sup 57}Fe Mössbauer spectroscopy is used as a principal method of investigation. Though electron microscopy has unveiled robust crystals (1-3 μm in size) of iron oxides, they are not manifested in the corresponding {sup 57}Fe Mössbauer spectra. The latter were acquired at 300 K and 4.2 K and resemble ferritin-like behavior.

  19. Basal Cell Carcinoma. Part 1: Basal Cell Carcinoma Has Come of Age.

    PubMed

    Deng, Min; Marsch, Amanda F; Petronic-Rosic, Vesna

    2015-01-01

    Almost 2 centuries after its recognition, basal cell carcinoma (BCC) remains the most common cancer worldwide, with a 30% overall lifetime risk in the United States and an incidence that continues to increase annually. The increasing incidence of BCC is multifactorial and likely correlates to multiple risk factors, including exposure to both ionizing and UV radiation. Despite its relatively indolent growth, what was once referred to as a rodent ulcer or basal cell epithelioma is now identified as a full-fledged malignancy. The authors describe the societal burden of this disease and characterize its malignant potential, emphasizing associated clinical and histopathologic prognostic features. PMID:26380507

  20. Basal body replication and cilogenesis in a suctorian, Tokophrya infusionum.

    PubMed

    Millecchia, L L; Rudzinska, M A

    1970-09-01

    Basal body replication and ciliogenesis in Tokophrya infusionum were studied in synchronized cultures. Basal body replication occurs during the 1st hr of reproduction, which in Tokophrya is by internal budding. The number of basal bodies increases from about 20 to over 300 within this period. New basal bodies develop in association with mature basal bodies; they are formed at right angles to the mature basal body as short "probasal" bodies, which elongate, slant upward, become parallel to the mature basal body, and elongate to the mature size. Ciliogenesis occurs only during reproduction; the nonreproducing adult is not ciliated, and has only 18-25 barren basal bodies. Cilia first appear as short bulges above the basal body. The axonemal structure is incomplete at first, with one or both central microtubules absent, and occasionally the B fibers of the outer doublets are missing. Several accessory fibers are associated with the basal bodies, both in the adult and during reproduction. One of the fibers appears only after the cilia have sprouted. The scheme of basal body replication and ciliogenesis in Tokophrya is compared to that reported in other organisms, and the role of the accessory fibers is discussed. PMID:4349131

  1. High porosity of basal till at Burroughs glacier, southeastern Alaska

    SciTech Connect

    Ronnert, L.; Mickelson, D.M. )

    1992-09-01

    Debris-rich basal ice at Burroughs glacier, southeastern Alaska, has 60 vol% to 70 vol% debris. Recently deposited basal till exceeds 60 vol% sediment with 30% to almost 40% porosity. Where basal ice is very rich in debris, basal till is deposited through melt out with only slight compaction of the debris. Porosity this high in till is commonly associated with subglacially deforming and dilated sediment. However, the recently deposited basal melt-out till at Burroughs glacier has not been deformed after deposition, but has porosity values similar to tills elsewhere interpreted to be subglacially deforming and dilated in an unfrozen state. High porosity can occur in basal melt-out till deposited directly by basal melt out.

  2. Evolution of sensory structures in basal metazoa.

    PubMed

    Jacobs, Dave K; Nakanishi, Nagayasu; Yuan, David; Camara, Anthony; Nichols, Scott A; Hartenstein, Volker

    2007-11-01

    Cnidaria have traditionally been viewed as the most basal animals with complex, organ-like multicellular structures dedicated to sensory perception. However, sponges also have a surprising range of the genes required for sensory and neural functions in Bilateria. Here, we: (1) discuss "sense organ" regulatory genes, including; sine oculis, Brain 3, and eyes absent, that are expressed in cnidarian sense organs; (2) assess the sensory features of the planula, polyp, and medusa life-history stages of Cnidaria; and (3) discuss physiological and molecular data that suggest sensory and "neural" processes in sponges. We then develop arguments explaining the shared aspects of developmental regulation across sense organs and between sense organs and other structures. We focus on explanations involving divergent evolution from a common ancestral condition. In Bilateria, distinct sense-organ types share components of developmental-gene regulation. These regulators are also present in basal metazoans, suggesting evolution of multiple bilaterian organs from fewer antecedent sensory structures in a metazoan ancestor. More broadly, we hypothesize that developmental genetic similarities between sense organs and appendages may reflect descent from closely associated structures, or a composite organ, in the common ancestor of Cnidaria and Bilateria, and we argue that such similarities between bilaterian sense organs and kidneys may derive from a multifunctional aggregations of choanocyte-like cells in a metazoan ancestor. We hope these speculative arguments presented here will stimulate further discussion of these and related questions. PMID:21669752

  3. Phylogenetic differences of mammalian basal metabolic rate are not explained by mitochondrial basal proton leak

    PubMed Central

    Polymeropoulos, E. T.; Heldmaier, G.; Frappell, P. B.; McAllan, B. M.; Withers, K. W.; Klingenspor, M.; White, C. R.; Jastroch, M.

    2012-01-01

    Metabolic rates of mammals presumably increased during the evolution of endothermy, but molecular and cellular mechanisms underlying basal metabolic rate (BMR) are still not understood. It has been established that mitochondrial basal proton leak contributes significantly to BMR. Comparative studies among a diversity of eutherian mammals showed that BMR correlates with body mass and proton leak. Here, we studied BMR and mitochondrial basal proton leak in liver of various marsupial species. Surprisingly, we found that the mitochondrial proton leak was greater in marsupials than in eutherians, although marsupials have lower BMRs. To verify our finding, we kept similar-sized individuals of a marsupial opossum (Monodelphis domestica) and a eutherian rodent (Mesocricetus auratus) species under identical conditions, and directly compared BMR and basal proton leak. We confirmed an approximately 40 per cent lower mass specific BMR in the opossum although its proton leak was significantly higher (approx. 60%). We demonstrate that the increase in BMR during eutherian evolution is not based on a general increase in the mitochondrial proton leak, although there is a similar allometric relationship of proton leak and BMR within mammalian groups. The difference in proton leak between endothermic groups may assist in elucidating distinct metabolic and habitat requirements that have evolved during mammalian divergence. PMID:21632624

  4. Uranium-series dating of mollusks and corals, and age of Pleistocene deposits, Chesapeake Bay area, Virginia and Maryland

    USGS Publications Warehouse

    Mixon, Robert B.; Szabo, B. J.; Owens, James Patrick

    1982-01-01

    Geologic mapping in conjunction with uranium-series dating of fossil mollusks and corals suggests that the low-lying ( < 17 m in altitude) terrace deposits in the central and southern Chesapeake Bay area include two main depositional sequences, each of which represents a high stand of the sea in late Pleistocene time. The older depositional sequence includes the Accomack and Omar beds of the Delmarva area, the fossiliferous deposits along the lower Rappahannock River, and the Norfolk Formation deposits west of the Suffolk scarp. These beds have yielded a single reliable coral age estimate of 184,000?20,000 years B.P., suggesting an early late Pleistocene age. The younger sequence, including the type beds of the Norfolk Formation and equivalent strata east of the Suffolk scarp, has yielded several coral ages ranging from about 62,000 to 86,000 years B.P. (including ages from our samples and previously reported age estimates); thus, it is clearly late Pleistocene in age. Groupings of ages obtained from our quahog analyses also suggest two transgressive sequences; however, the estimated quahog ages are consistently younger than ages based on coral samples from the same and equivalent stratigraphic units. Stratigraphic, paleoclimatic, and geomorphic data suggest that the estimated uranium-series age of 71,000?7,000 years B.P. for the type beds of the Norfolk, obtained by averaging our coral dates, may be too young by as much as several tens of thousands of years. A postulated equivalency of the type Norfolk beds, upper Pleistocene deposits near Charleston, S.C. (apparent uranium-series age = 95,000?5,000 years), and deposits in the Caribbean area thought to represent the highest sea stand during the last interglacial period (apparent age, 125,000?10,000 years) implies diagenetic modification of coralline material possibly in part because of regional differences in depositional and postdepositional environments.

  5. Basal area from photos.... Is it possible?

    NASA Astrophysics Data System (ADS)

    Sparrow, B.; Ward, B.; Armston, J.; Schaefer, M.; Thurgate, N.; van den Hengel, A.; Lowe, A.; Phinn, S. R.

    2013-12-01

    This paper describes collaborative work conducted between the Ausplots and AusCover facilities within Australia's Terrestrial Ecosystem Research Network (TERN) and the Australian Centre for Visual Technologies (ACVT) to develop new photopoint collection methodologies for use by terrestrial ecologists. These photopoints are being collected at Ausplots survey sites throughout rangeland environments across Australia along with a wide suite of environmental measures, including a range of soil, vegetation species and structure and genetics information, with currently around 270 sites out of 700 collected. These collections are intended to augment the ecological data collected at each site and provide a record of that time. Similar measures are also being collected at Auscover calibration and validation sites. Our photopoints incorporate three sets of overlapping photographs, each collected from exposure points at the vertices of an equilateral triangle with sides of 2.5 m located around the centre point of the field site. The photos from each exposure point typically overlap by 50% and at least one photo in each series include a calibration target mounted on a pole at the centre of the exposure points. These photographs are then processed to create a range of data products. Seamless photo panoramas are constructed for each field site and are stored with the relevant site data allowing ecologists utilising the ecological data to also include the environment in which that data were collected. Point clouds are also produced allowing a three dimensional view of the site and potentially allowing similar analysis, albeit at lower precision, to that of terrestrial Lidar systems. These three dimensional site reconstructions are used to measure stem diameters, and calculate basal area, which are summed for the site, providing a measure of basal area per hectare when the visible distance is taken into account. This method is potentially more accurate than rapid techniques such as

  6. Radiation-induced basal cell carcinoma

    PubMed Central

    Zargari, Omid

    2015-01-01

    Background: The treatment of tinea capitis using radiotherapy was introduced at the beginning of the twentieth century. A variety of cancers including basal cell carcinoma (BCC) are seen years after this treatment. Objective: We sought to determine the clinical characteristics of BCCs among irradiated patients. Methods: The clinical records of all patients with BCC in a clinic in north of Iran were reviewed. Results: Of the 58 cases of BCC, 29 had positive history for radiotherapy in their childhood. Multiple BCCs were seen in 79.3% and 10.3% of patients with history and without history of radiotherapy, respectively. Conclusions: X-ray radiation is still a major etiologic factor in developing BCC in northern Iran. Patients with positive history for radiotherapy have higher rate of recurrence. PMID:26114066

  7. How to achieve a predictable basal insulin?

    PubMed

    Kurtzhals, P

    2005-09-01

    The development of insulin analogues over the last two decades have aimed at optimising the pharmacokinetic profile of subcutaneously injected insulin for therapeutic use in diabetes mellitus. Rapid acting analogues were successfully engineered and marketed in the late 1990's. In engineering long-acting analogues it has been a particular challenge to obtain action profiles that would be predictable from day to day in the same person. The most recent approach has been to acylate the insulin molecule with a fatty acid which provides the insulin molecule with a specific affinity for albumin. The first clinically available agent of this type is insulin detemir. Pharmacological studies have shown that reversible albumin binding will protract absorption following subcutaneous injection but still allow the insulin molecule to be recognised by the insulin receptor following dissociation from the carrier protein. Moreover, the molecular features of insulin detemir are attractive in that the molecule can be formulated as a neutral aqueous solution and does not precipitate after injection. Together with an important buffering mechanism effected by plasma albumin binding, this explains a highly significant reduction of within-subject variability of pharmacodynamic response observed in repeat isoglycaemic clamp studies where insulin detemir was compared to other basal insulin products. No safety considerations have been identified in using albumin as an insulin carrier to protract and buffer insulin action. In assessing the clinical attractiveness of insulin analogues, it is furthermore critically important to consider how the molecular modifications impact efficacy and safety. A number of pharmacological studies have shown that insulin detemir overall retains the molecular pharmacological properties of native human insulin, including a physiological balance between metabolic and mitogenic potencies. Taken together, insulin detemir provides an attractive novel approach for

  8. Concentrated insulins: the new basal insulins

    PubMed Central

    Lamos, Elizabeth M; Younk, Lisa M; Davis, Stephen N

    2016-01-01

    Introduction Insulin therapy plays a critical role in the treatment of type 1 and type 2 diabetes mellitus. However, there is still a need to find basal insulins with 24-hour coverage and reduced risk of hypoglycemia. Additionally, with increasing obesity and insulin resistance, the ability to provide clinically necessary high doses of insulin at low volume is also needed. Areas covered This review highlights the published reports of the pharmacokinetic (PK) and glucodynamic properties of concentrated insulins: Humulin-R U500, insulin degludec U200, and insulin glargine U300, describes the clinical efficacy, risk of hypoglycemic, and metabolic changes observed, and finally, discusses observations about the complexity of introducing a new generation of concentrated insulins to the therapeutic market. Conclusion Humulin-R U500 has a similar onset but longer duration of action compared with U100 regular insulin. Insulin glargine U300 has differential PK/pharmacodynamic effects when compared with insulin glargine U100. In noninferiority studies, glycemic control with degludec U200 and glargine U300 is similar to insulin glargine U100 and nocturnal hypoglycemia is reduced. Concentrated formulations appear to behave as separate molecular entities when compared with earlier U100 insulin analog compounds. In the review of available published data, newer concentrated basal insulins may offer an advantage in terms of reduced intraindividual variability as well as reducing the injection burden in individuals requiring high-dose and large volume insulin therapy. Understanding the PK and pharmacodynamic properties of this new generation of insulins is critical to safe dosing, dispensing, and administration. PMID:27022271

  9. Fast Modulation of Visual Perception by Basal Forebrain Cholinergic Neurons

    PubMed Central

    Estandian, Daniel; Xu, Min; Kwan, Alex C.; Lee, Seung-Hee; Harrison, Thomas C.; Feng, Guoping; Dan, Yang

    2014-01-01

    The basal forebrain provides the primary source of cholinergic input to the cortex, and it plays a crucial role in promoting wakefulness and arousal. However, whether rapid changes in basal forebrain neuron spiking in awake animals can dynamically influence sensory perception is unclear. Here we show that basal forebrain cholinergic neurons rapidly regulate cortical activity and visual perception in awake, behaving mice. Optogenetic activation of the cholinergic neurons or their V1 axon terminals improved performance of a visual discrimination task on a trial-by-trial basis. In V1, basal forebrain activation enhanced visual responses and desynchronized neuronal spiking, which could partly account for the behavioral improvement. Conversely, optogenetic basal forebrain inactivation decreased behavioral performance, synchronized cortical activity and impaired visual responses, indicating the importance of cholinergic activity in normal visual processing. These results underscore the causal role of basal forebrain cholinergic neurons in fast, bidirectional modulation of cortical processing and sensory perception. PMID:24162654

  10. Drosophila melanogaster as a model for basal body research.

    PubMed

    Jana, Swadhin Chandra; Bettencourt-Dias, Mónica; Durand, Bénédicte; Megraw, Timothy L

    2016-01-01

    The fruit fly, Drosophila melanogaster, is one of the most extensively studied organisms in biological research and has centrioles/basal bodies and cilia that can be modelled to investigate their functions in animals generally. Centrioles are nine-fold symmetrical microtubule-based cylindrical structures required to form centrosomes and also to nucleate the formation of cilia and flagella. When they function to template cilia, centrioles transition into basal bodies. The fruit fly has various types of basal bodies and cilia, which are needed for sensory neuron and sperm function. Genetics, cell biology and behaviour studies in the fruit fly have unveiled new basal body components and revealed different modes of assembly and functions of basal bodies that are conserved in many other organisms, including human, green algae and plasmodium. Here we describe the various basal bodies of Drosophila, what is known about their composition, structure and function. PMID:27382461

  11. Late Neogene evolution of the East Asian monsoon revealed by terrestrial mollusk record in Western Chinese Loess Plateau: From winter to summer dominated sub-regime

    NASA Astrophysics Data System (ADS)

    Li, Fengjiang; Rousseau, Denis-Didier; Wu, Naiqin; Hao, Qingzhen; Pei, Yunpeng

    2008-10-01

    More and more evidence indicates that the onset of the East Asian (EA) monsoon can be traced back to the Oligocene-Miocene boundary (at about 23 Ma). However, the process of its evolution is still less well-known until now. Here we investigate its late Neogene evolution by analyzing a terrestrial mollusk sequence, from the Chinese Loess Plateau (CLP), covering the period between 7.1 and 3.5 Ma. Considering the modern ecological requirements of these organisms, we were able to define two groups of cold-aridiphilous (CA) and thermo-humidiphilous (TH) species, representing the EA winter and summer monsoon variations, respectively, as previously defined in the Quaternary glacial-interglacial cycles. Variations in these two groups indicate two different monsoon dominated periods during 7.1-3.5 Ma. First, between 7.1 and 5.5 Ma, the EA winter monsoon, with a 100-kyr periodicity, was dominant. Second, between 5.1 and 4 Ma, the EA summer monsoon dominated, with a 41-kyr periodicity. Furthermore, our mollusk record yields valuable evidence for a late Miocene-Pliocene transition of about 400 kyr from winter monsoon dominated towards summer monsoon dominated, associated with a periodicity transition from weak 100 kyr to 41 kyr. The strengthened winter monsoon interval, with a 100-kyr periodicity, is coeval with orbital-scale global ice-volume changes, in conjunction with the uplift of the Tibetan Plateau which probably reinforced the winter monsoon sub-regime. Conversely, closures of the Panama and Indonesian seaways, associated with changes in obliquity between 5.1 and 4 Ma, are probably major forcing factors for the observed dominant summer monsoon with 41-kyr frequency, favoring heat and moisture transports between low and high latitudes to allow TH mollusks to grow and develop in the CLP.

  12. An assemblage of mollusks associated with the high latitude scleractinian coral Alveopora japonica (Eguchi 1968) in Jeju Island, off the south coast of Korea

    NASA Astrophysics Data System (ADS)

    Noseworthy, Ronald G.; Hong, Hyun-Ki; Keshavmurthy, Shashank; Lee, Hee-Jung; Jeung, Hee-Do; Ju, Se-Jong; Kim, Jong-Bin; Jung, Sukgeun; Choi, Kwang-Sik

    2016-03-01

    Corals reefs and communities support a wide range of flora and fauna. The complete richness and abundance of faunal communities in either coral reefs or communities is not fully understood. This is especially true for high-latitude coral communities. In this work, we carried out an analysis of an Alveopora japonica associated mollusk assemblage, in Jeju Island, Korea. A. japonica is one of the major coral species present in high abundance (88-155 colonies m-2), with a high recruitment rate (7.8 juvenile corals m-2 yr-1) in Jeju Island, and may serve as a habitat for other benthic organisms. In 2012, a total number of 579 A. japonica colonies with sizes ranging between 15.1-346.7 cm2 in the surface area were collected from a 1m× 10m quadrat installed at a depth of 10 m at Keumneung, on the northwest coast of Jeju Island. Numerous benthic invertebrates were found to be associated with A. japonica colonies. Twenty-seven bivalves and gastropods were identified, including a boring mytilid, Lithophaga curta, and an arcid, Barbatia stearnsi. A zonalgeographical examination of the distribution ranges of these mollusks revealed a majority of warmer water species. Our observations also showed that A. japonica may be providing a habitat to grazing gastropod, Turbo cornutus, and encrusting Spondylidae and Chamidae bivalves. A. japonica forms a coral carpet with a distinct assemblage of bivalves. It is thought that the presence of these mollusks species in the coral indicates its use as a nursery for juvenile species, a ready food supply of organic detritus, and a refuge from predators.

  13. Systematic detection of BMAA (β-N-methylamino-l-alanine) and DAB (2,4-diaminobutyric acid) in mollusks collected in shellfish production areas along the French coasts.

    PubMed

    Réveillon, Damien; Séchet, Véronique; Hess, Philipp; Amzil, Zouher

    2016-02-01

    The neurotoxin β-N-methylamino-l-alanine (BMAA) is naturally present in some microalgal species in the marine environment. The accumulation of BMAA has widely been observed in filter-feeding bivalves that are known to consume primary producers constituting the base of complex aquatic food webs. This study was performed to assess the occurrence of BMAA and isomers in mollusks collected from nine representative shellfish production areas located on the three French coasts (Channel, Atlantic and Mediterranean sites). The use of a highly selective and sensitive HILIC-MS/MS method, with D5DAB as internal standard, revealed the systematic detection of BMAA and DAB, in concentrations ranging from 0.20 to 6.7 μg g(-1) dry weight of digestive gland tissues of mollusks. While we detected BMAA in four strains of diatoms in a previous study, here BMAA was only detected in one diatom species previously not investigated out of the 23 microalgal species examined (belonging to seven classes). The concentrations of BMAA and DAB in mussels and oysters were similar at different sampling locations and despite the high diversity of phytoplankton populations that mollusks feed on at these locations. Only small variations of BMAA and DAB levels were observed and these were not correlated to any of the phytoplankton species reported. Therefore, extensive research should be performed on both origin and metabolism of BMAA in shellfish. The levels observed in this study are similar to those found in other studies in France or elsewhere. A previous study had related such levels to a cluster of Amyotrophic Lateral Sclerosis in the South of France; hence the widespread occurrence of BMAA in shellfish from all coasts in France found in this study suggests the need for further epidemiological and toxicological studies to establish the levels that are relevant for a link between the consumption of BMAA-containing foodstuffs and neurodegenerative diseases. PMID:26615827

  14. Mechanisms of platelet adhesion to the basal lamina.

    PubMed Central

    Huang, T. W.; Benditt, E. P.

    1978-01-01

    The human glomerular basal lamina (HGBL) is composed of collagenous and noncollagenous glycoproteins. We assessed the role played by each costituent in platelet-basal-lamina interaction by selective cleavage and removal of each component by clostridial collagenase or by pepsin. When noncollagenous proteins are removed from HGBL, human platelets exhibit littel reactivity toward the residual collagen framework of the isolated basal lamina. With the noncollagen matrix of basal lamina, after removal of the bulk of the collagen, platelet adhesion and spreading proceed normally in the presence of divalent cations, similar to what occurs on intact basal lamina. No platelet degranulation or aggregation is observed. The results indicate that the basal lamina collagen, even in its native packing arrangement, lacks affinity for platelet adhesion and is incapable of triggering platelet release reactions. Platelet adhesion and spreading on the basal lamina appears to depend primarily on the presence of the noncollagen components and to require divalent cations. The data suggest the presence on platelets of receptors for basal lamina distinct from those for interstitial collagens. These receptors activate a unique modulation of platelet behavior, ie, adhesion and spreading without degranulation. A difference in biologic function of the basal lamina and interstitial collagens is apparent in these experiments. Images Figure 4 Figure 5 Figure 6 Figure 1 Figure 2 Figure 3 PMID:210672

  15. Site-specific basal body duplication in Chlamydomonas.

    PubMed

    O'Toole, Eileen T; Dutcher, Susan K

    2014-02-01

    Correct centriole/basal body positioning is required for numerous biological processes, yet how the cell establishes this positioning is poorly understood. Analysis of centriolar/basal body duplication provides a key to understanding basal body positioning and function. Chlamydomonas basal bodies contain structural features that enable specific triplet microtubules to be specified. Electron tomography of cultures enriched in mitotic cells allowed us to follow basal body duplication and identify a specific triplet at which duplication occurs. Probasal bodies elongate in prophase, assemble transitional fibers (TF) and are segregated with a mature basal body near the poles of the mitotic spindle. A ring of nine-singlet microtubules is initiated at metaphase, orthogonal to triplet eight. At telophase/cytokinesis, triplet microtubule blades assemble first at the distal end, rather than at the proximal cartwheel. The cartwheel undergoes significant changes in length during duplication, which provides further support for its scaffolding role. The uni1-1 mutant contains short basal bodies with reduced or absent TF and defective transition zones, suggesting that the UNI1 gene product is important for coordinated probasal body elongation and maturation. We suggest that this site-specific basal body duplication ensures the correct positioning of the basal body to generate landmarks for intracellular patterning in the next generation. PMID:24166861

  16. Insulin Degludec, The New Generation Basal Insulin or Just another Basal Insulin?

    PubMed

    Nasrallah, Sami N; Reynolds, L Raymond

    2012-01-01

    The advances in recombinant DNA technology have led to an improvement in the properties of currently available long-acting insulin analogs. Insulin degludec, a new generation ultra-long-acting basal insulin, currently in phase 3 clinical trials, has a promising future in clinical use. When compared to its rival basal insulin analogs, a longer duration of action and lower incidence of hypoglycemic events in both type 1 and type 2 diabetic patients has been demonstrated.1,2 Its unique mechanism of action is based on multihexamer formation after subcutaneous injection. This reportedly allows for less pharmacodynamic variability and within-subject variability than currently available insulin analogs, and a duration of action that is over 24 hours.3 The lack of proof of carcinogenicity with insulin degludec is yet another factor that would be taken into consideration when choosing the optimal basal insulin for a diabetic individual.4 A formulation of insulin degludec with insulin aspart, Insulin degludec 70%/aspart 30%, may permit improved flexibly of dosing without compromising glycemic control or safety.5. PMID:22879797

  17. Distinctive Patterns of CTNNB1 (β-Catenin) Alterations in Salivary Gland Basal Cell Adenoma and Basal Cell Adenocarcinoma.

    PubMed

    Jo, Vickie Y; Sholl, Lynette M; Krane, Jeffrey F

    2016-08-01

    Salivary gland basaloid neoplasms are diagnostically challenging. Limited publications report that some basal cell adenomas harbor CTNNB1 mutations, and nuclear β-catenin expression is prevalent. We evaluated β-catenin expression in basal cell adenomas and adenocarcinomas in comparison with salivary tumors in the differential diagnosis and performed targeted genetic analysis on a subset of cases. β-catenin immunohistochemistry was performed on formalin-fixed, paraffin-embedded whole sections from 73 tumors. Nuclear staining was scored semiquantitatively by extent and intensity. DNA was extracted from 6 formalin-fixed, paraffin-embedded samples (5 basal cell adenomas, 1 basal cell adenocarcinoma) for next-generation sequencing. Nuclear β-catenin staining was present in 18/22 (82%) basal cell adenomas; most were diffuse and strong and predominant in the basal component. Two of 3 basal cell adenocarcinomas were positive (1 moderate focal; 1 moderate multifocal). All adenoid cystic carcinomas (0/20) and pleomorphic adenomas (0/20) were negative; 2/8 epithelial-myoepithelial carcinomas showed focal nuclear staining. Most β-catenin-negative tumors showed diffuse membranous staining in the absence of nuclear staining. Four of 5 basal cell adenomas had exon 3 CTNNB1 mutations, all c.104T>C (p.I35T). Basal cell adenocarcinoma showed a more complex genomic profile, with activating mutations in PIK3CA, biallelic inactivation of NFKBIA, focal CYLD deletion, and without CTNNB1 mutation despite focal β-catenin expression. Nuclear β-catenin expression has moderate sensitivity (82%) for basal cell adenoma but high specificity (96%) in comparison with its morphologic mimics. CTNNB1 mutation was confirmed in most basal cell adenomas tested, and findings in basal cell adenocarcinoma suggest possible tumorigenic mechanisms, including alterations in PI3K and NF-κB pathways and transcriptional regulation. PMID:27259009

  18. Heterogeneity of basal keratinocytes: nonrandom distribution of thymidine-labeled basal cells in confluent cultures is not a technical artifact

    SciTech Connect

    Milstone, L.M.; LaVigne, J.F.

    1985-06-01

    Basal surface autoradiography of (/sup 3/H)dThd-labeled, confluent, keratinocyte cultures reveals that proliferating cells have a nonrandom, patterned distribution. Unlabeled cells, likewise, appear nonrandomly in clusters. The authors show here that failure to detect DNA synthesis in some basal cells in culture is not an artifact caused either by physical separation of the labeled nuclei from the radiographic emulsion or by a diffusion barrier that would prevent (/sup 3/H)dThd from reaching basal cells.

  19. Nevoid basal cell carcinoma syndrome (Gorlin syndrome)

    PubMed Central

    Lo Muzio, Lorenzo

    2008-01-01

    Nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin syndrome, is a hereditary condition characterized by a wide range of developmental abnormalities and a predisposition to neoplasms. The estimated prevalence varies from 1/57,000 to 1/256,000, with a male-to-female ratio of 1:1. Main clinical manifestations include multiple basal cell carcinomas (BCCs), odontogenic keratocysts of the jaws, hyperkeratosis of palms and soles, skeletal abnormalities, intracranial ectopic calcifications, and facial dysmorphism (macrocephaly, cleft lip/palate and severe eye anomalies). Intellectual deficit is present in up to 5% of cases. BCCs (varying clinically from flesh-colored papules to ulcerating plaques and in diameter from 1 to 10 mm) are most commonly located on the face, back and chest. The number of BBCs varies from a few to several thousand. Recurrent jaw cysts occur in 90% of patients. Skeletal abnormalities (affecting the shape of the ribs, vertebral column bones, and the skull) are frequent. Ocular, genitourinary and cardiovascular disorders may occur. About 5–10% of NBCCS patients develop the brain malignancy medulloblastoma, which may be a potential cause of early death. NBCCS is caused by mutations in the PTCH1 gene and is transmitted as an autosomal dominant trait with complete penetrance and variable expressivity. Clinical diagnosis relies on specific criteria. Gene mutation analysis confirms the diagnosis. Genetic counseling is mandatory. Antenatal diagnosis is feasible by means of ultrasound scans and analysis of DNA extracted from fetal cells (obtained by amniocentesis or chorionic villus sampling). Main differential diagnoses include Bazex syndrome, trichoepithelioma papulosum multiplex and Torre's syndrome (Muir-Torre's syndrome). Management requires a multidisciplinary approach. Keratocysts are treated by surgical removal. Surgery for BBCs is indicated when the number of lesions is limited; other treatments include laser ablation, photodynamic

  20. Constraining riverine δ13C-DIC using Late Cretaceous and Early Paleogene freshwater bivalve mollusks (Unionoidea) form Montana

    NASA Astrophysics Data System (ADS)

    Gillikin, D. P.; Goodwin, D. H.; Davidson, M.; Hartman, J.

    2014-12-01

    Interpretation of carbon isotope variation in freshwater unionoid mollusk shells (δ13CSHELL) is not straightforward because of the variable contributions of metabolic (i.e., food) and dissolved inorganic carbon (DIC). Bivalve shells typically contain between 0 and 50% metabolic carbon (CM), which has a δ13C value close to the animal's food source. In marine systems, the food source (usually phytoplankton) has a δ13C value typically around -20 ‰ and a d13CDIC value around ~0 ‰. In freshwater systems, these numbers can vary considerably, with food sources ranging from -35 to -10 ‰. Typically, δ13C-DIC values range between -25 to 0‰ and are dependent on numerous factors; carbonate weathering and equilibrium with the atmosphere typically leading to high values and respiration of organic matter and oxidation of methane leading to lower values. Therefore, δ13C-DIC values reflect numerous processes occurring in the watershed. Nevertheless, here we suggest δ13CSHELL values can constrain the lower bounds of riverine δ13C-DIC values, despite the influence of CM. The metabolic end-member δ13C value is typically lower than the DIC end member and consequently will lead to higher calculated δ13C-DIC when using δ13CSHELL values. Therefore, if the CM fraction is set to 0 %, δ13CSHELL values will provide the lowest possible riverine δ13C-DIC values (after accounting for fractionation). Applying this method to modern shells from waters with known δ13C-DIC values (ranging from -3.2 to -12.8 ‰) results in calculated δ13C-DIC values from -6.0 to -12.4 ‰, which is close to measured DIC data from the waters in which the mussel grew. This can then in turn be applied to well-preserved fossil shells. Freshwater unionoid shells from the uppermost Cretaceous Hell Creek Formation and the lower Paleogene Fort Union Formation are exceptionally well preserved. Applying this method to these shells results in δ13C-DIC values ranging from -6 to -11‰, which is consistent

  1. A basal carbon concentrating mechanism in plants?

    PubMed

    Zabaleta, Eduardo; Martin, M Victoria; Braun, Hans-Peter

    2012-05-01

    Many photosynthetic organisms have developed inorganic carbon (Ci) concentrating mechanisms (CCMs) that increase the CO₂ concentration within the vicinity of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). Several CCMs, such as four carbon (C4) and crassulacean acid metabolism (CAM), bicarbonate accumulation systems and capsular structures around RubisCO have been described in great detail. These systems are believed to have evolved several times as mechanisms that acclimate organisms to unfavourable growth conditions. Based on recent experimental evidence we propose the occurrence of another more general CCM system present in all plants. This basal CCM (bCCM) is supposed to be composed of mitochondrial carbonic anhydrases (a β-type carbonic anhydrase and the γ-type carbonic anhydrase domain of the mitochondrial NADH dehydrogenase complex) and probably further unknown components. The bCCM is proposed to reduce leakage of CO₂ from plant cells and allow efficient recycling of mitochondrial CO₂ for carbon fixation in chloroplasts. PMID:22404837

  2. Fluctuating selection on basal metabolic rate.

    PubMed

    Nilsson, Johan F; Nilsson, Jan-Åke

    2016-02-01

    BMR (Basal metabolic rate) is an important trait in animal life history as it represents a significant part of animal energy budgets. BMR has also been shown to be positively related to sustainable work rate and maximal thermoregulatory capacity. To this date, most of the studies have focused on the causes of interspecific and intraspecific variation in BMR, and fairly little is known about the fitness consequences of different metabolic strategies. In this study, we show that winter BMR affects local survival in a population of wild blue tits (Cyanistes caeruleus), but that the selection direction differs between years. We argue that this fluctuating selection is probably a consequence of varying winter climate with a positive relation between survival and BMR during cold and harsh conditions, but a negative relation during mild winters. This fluctuating selection can not only explain the pronounced variation in BMR in wild populations, but will also give us new insights into how energy turnover rates can shape the life-history strategies of animals. Furthermore, the study shows that the process of global warming may cause directional selection for a general reduction in BMR, affecting the general life-history strategy on the population level. PMID:26839687

  3. Anti-basal ganglia antibodies in PANDAS.

    PubMed

    Singer, Harvey S; Loiselle, Christopher R; Lee, Olivia; Minzer, Karen; Swedo, Susan; Grus, Franz H

    2004-04-01

    An autoimmune-mediated mechanism involving molecular mimicry has been proposed for a variety of pediatric movement disorders that occur after a streptococcal infection. In this study, anti-basal ganglia antibodies (ABGA) were measured in 15 children with the diagnosis of pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS) and compared with those in 15 controls. ELISA and Western immunoblotting (WB) methods were used to detect ABGA against supernatant (S1), pellet (P2), and synaptosomal preparations from adult postmortem caudate, putamen, and globus pallidus. ELISA optical density values did not differ between PANDAS patients and controls across all preparations. Immunoblotting identified multiple bands in all subjects with no differences in the number of bands or their total density. Discriminant analysis, used to assess mean binding patterns, showed that PANDAS patients differed from controls only for the caudate S1 fraction (Wilks' lambda = 0.0236, P < 0.0002), with PANDAS-primarily tic subjects providing the greatest discrimination. Among the epitopes contributing to differences between PANDAS and control in the caudate S1 fraction, mean binding to the epitope at 183 kDa was the most different between groups. In conclusion, ELISA measurements do not differentiate between PANDAS and controls, suggesting a lack of major antibody changes in this disorder. Further immunoblot analyses using a caudate supernatant fraction are required to completely exclude the possibility of minor antibody repertoire differences in PANDAS subjects, especially in those who primarily have tics. PMID:15077238

  4. Basal activity of GIRK5 isoforms.

    PubMed

    Salvador, Carolina; Mora, Silvia I; Ordaz, Benito; Antaramian, Anaid; Vaca, Luis; Escobar, Laura I

    2003-02-14

    G protein-coupled inwardly rectifying K(+) channels (GIRK or Kir3) form functional heterotetramers gated by Gbetagamma subunits. GIRK channels are critical for functions as diverse as heart rate modulation and neuronal post-synaptic inhibition. GIRK5 (Kir3.5) is the oocyte homologue of the mammalian GIRK subunits that conform the K(ACh) channel. It has been claimed that even when the oocytes express GIRK5 proteins they do not form functional channels. However, the GIRK5 gene shows three initiation sites that suggest the existence of three isoforms. In a previous work we demonstrated the functionality of homomultimers of the shortest isoform overexpressed in the own oocytes. Remarkably, the basal GIRK5-Delta25 inward currents were not coupled to the activation of a G-protein receptor in the oocytes. These results encouraged us to study this channel in another expression system. In this work we show that Sf21 insect cells can be successfully transfected with this channel. GIRK5-Delta25 homomultimers produce time-dependent inward currents only with GTPgammaS in the recording pipette. Therefore, alternative modes of stimulus input to heterotrimeric G-proteins should be present in the oocytes to account for these results. PMID:12535718

  5. The effective treatment of basal cell carcinoma.

    PubMed

    Skelton, Lucy Anne

    Basal cell carcinoma (BCC) accounts for 75% of all skin cancers and its incidence is rising by between 3-8% each year (Szeimies and Karrer, 2006). As a result, the development of new therapeutic strategies and treatment methods for the removal of BCC is crucial in combating what is a growing problem. Surgical techniques, such as Mohs micrographic surgery, cryotherapy/cryosurgery, curettage and carbon dioxide laser therapy, as well as non-surgical techniques, such as radiotherapy, are recognized as potential options. The aim of this article is to critically review some of the current literature in order to substantiate the efficacy of destructive and non-surgical techniques as reliable alternatives to surgery for the management/removal of BCCs. The success rate, cosmetic outcome, pain and discomfort, recurrence rates, and the cost associated with each method are explored and discussed. Results of the review indicate that no one treatment is completely superior. According to the research, simple excision and Mohs micrographic surgery provide the lowest recurrence rates. However, in relation to success rates, patients tolerance of the treatment and cosmetic outcomes, and depending on the type of BCC involved, other treatment methods do offer reliable alternatives. PMID:19329898

  6. New basal cell carcinoma susceptibility loci

    PubMed Central

    Stacey, Simon N.; Helgason, Hannes; Gudjonsson, Sigurjon A.; Thorleifsson, Gudmar; Zink, Florian; Sigurdsson, Asgeir; Kehr, Birte; Gudmundsson, Julius; Sulem, Patrick; Sigurgeirsson, Bardur; Benediktsdottir, Kristrun R.; Thorisdottir, Kristin; Ragnarsson, Rafn; Fuentelsaz, Victoria; Corredera, Cristina; Gilaberte, Yolanda; Grasa, Matilde; Planelles, Dolores; Sanmartin, Onofre; Rudnai, Peter; Gurzau, Eugene; Koppova, Kvetoslava; Nexø, Bjørn A.; Tjønneland, Anne; Overvad, Kim; Jonasson, Jon G.; Tryggvadottir, Laufey; Johannsdottir, Hrefna; Kristinsdottir, Anna M.; Stefansson, Hreinn; Masson, Gisli; Magnusson, Olafur T.; Halldorsson, Bjarni V.; Kong, Augustine; Rafnar, Thorunn; Thorsteinsdottir, Unnur; Vogel, Ulla; Kumar, Rajiv; Nagore, Eduardo; Mayordomo, José I.; Gudbjartsson, Daniel F.; Olafsson, Jon H.; Stefansson, Kari

    2015-01-01

    In an ongoing screen for DNA sequence variants that confer risk of cutaneous basal cell carcinoma (BCC), we conduct a genome-wide association study (GWAS) of 24,988,228 SNPs and small indels detected through whole-genome sequencing of 2,636 Icelanders and imputed into 4,572 BCC patients and 266,358 controls. Here we show the discovery of four new BCC susceptibility loci: 2p24 MYCN (rs57244888[C], OR=0.76, P=4.7 × 10−12), 2q33 CASP8-ALS2CR12 (rs13014235[C], OR=1.15, P=1.5 × 10−9), 8q21 ZFHX4 (rs28727938[G], OR=0.70, P=3.5 × 10−12) and 10p14 GATA3 (rs73635312[A], OR=0.74, P=2.4 × 10−16). Fine mapping reveals that two variants correlated with rs73635312[A] occur in conserved binding sites for the GATA3 transcription factor. In addition, expression microarrays and RNA-seq show that rs13014235[C] and a related SNP rs700635[C] are associated with expression of CASP8 splice variants in which sequences from intron 8 are retained. PMID:25855136

  7. What has happened to the benthic mollusks of the Yellow Sea in the near half century? Comparison on molluscan biodiversity between 1959 and 2007

    NASA Astrophysics Data System (ADS)

    Zhang, Junlong; Zhang, Suping; Zhang, Shuqian; Du, Yongfen; Xu, Fengshan

    2016-02-01

    In recent years, the ecological environment in the Yellow Sea has changed greatly, as it has been influenced by climate change and various human activities. In this study, molluscan biodiversity at 42 sampling sites sampled in July 1959 and June 2007 were compared. The result showed that biomass of mollusks changed slight (p=0.981; 4.92 g/m2vs 4.88 g/m2), while abundances were higher in 2007 (p=0.038<0.05; 81.79 ind/m2vs 45.10 ind/m2), and the number of species (p=0.021<0.05), Margalef's species richness (p=0.005<0.01), and Shannon-Wiener index (p=0.006<0.01) was higher in 1959. The sites in the Yellow Sea Cold Water Mass occupied area, which were dominated by cold water species, were clustered together by the agglomerative classification method and the community there was rather stable, whilst great changes have occurred for the communities sited in the coastal waters. It is indicated that molluscan communities of the Yellow Sea were in undisturbed condition in 1959 (W= 0.051), but were severely impacted in 2007 (W= -0.058) resulting from the abundance/biomass comparison (ABC) method. Though the abundance increased, the biodiversity decreased and the community structure changed greatly. Generally, temperature, water depth, and salinity were major factors that affected the distribution of mollusks in the Yellow Sea.

  8. [Abundance and richness of mollusks and crustaceans associated to the submerged roots of red mangrove (Rhizophora mangle) at Bocaripo Lagoon, Sucre, Venezuela].

    PubMed

    Cedeño, Jennellis; Jiménez Prieto, Mayré; Pereda, Luisana; Allen, Thays

    2010-10-01

    Mangrove roots are important habitats for many species. The abundance and richness of mollusks and crustaceans associated with the roots demerged of Rhizophora mangle was studied. The samples were gathered between February 2005 and January 2006, in Bocaripo lagoon, north coast of Sucre state, Venezuela. Five stations were established inside the lagoon; on every station two roots were chosen at random, put in plastic bags and scraped. The associated organisms were separated by taxa and fixed in 10% formaldehyde. One thousand ninety two specimens of mollusks, distributed in two classes: Bivalve and Gastropod were collected. Bivalve was the most abundant with 943 individuals. The most representative family was Mytilidae with 6 species, being Musculus lateralis the dominant species. The crustaceans were represented by 372 organisms, belonging to the class Malacostraca, where Panopeus herbstii (169 ind.) was the most abundant species. The families Panopeidae, Porcellanidae and Majidae had the highest number of species. Maximum abundance was in February (224 ind.), with a richness of 25 species and the minimums in November (45 ind.) and a richness of 12 species. The stations 1 and 5 presented the major abundance and richness of organisms, which could be related to environmental conditions favorable, as the major availability of microhabitats and nourishing offer; on the contrary the station 4, presented a more inhospitable environment, due to the high values in the salinity and temperature, which contributes with the minor abundance and richness of the present species. PMID:21302531

  9. Removal of Cd2+ from contaminated water by nano-sized aragonite mollusk shell and the competition of coexisting metal ions.

    PubMed

    Du, Yang; Zhu, Lingyan; Shan, Guoqiang

    2012-02-01

    The potential of using nano-sized aragonite mollusk shell (nano-Bio-ARA) to remove Cd(2+) from contaminated water was investigated by comparing the sorption kinetics and isotherms with the nano-sized calcite-type mollusk shell (nano-Bio-CAL) and nano-sized geological calcite (nano-Geo-CAL). Nano-Bio-ARA displayed extremely high sorption capacity to Cd(2+) (8.91mmol/g), much higher than nano-Bio/Geo-CAL, and many other natural or engineered materials. The results of thermodynamic experiments indicated that the sorption of Cd(2+) on the nano-ARA was a spontaneous and endothermic process. The coexisting metals in the solution displayed competition effect to the sorption of Cd(2+) on nano-Bio-ARA in the following order: Cu(2+)>Cr(3+)>Pb(2+)>Zn(2+)>Ca(2+). EDTA impeded the sorption of Cd(2+) on nano-Bio-ARA due to its strong chelating capacity to Cd(2+) in the solution. The results demonstrate that nano-Bio-ARA is a potential high-effective material to treat Cd(2+) contaminated water. PMID:22047918

  10. Using watershed characteristics, sediment, and tissue of resident mollusks to identify potential sources of trace elements to streams in a complex agricultural landscape.

    PubMed

    Ciparis, Serena; Schreiber, Madeline E; Voshell, J Reese

    2012-05-01

    Trace elements used in animal feed additives can be introduced to aquatic environments through application of manures from animal feeding operations to agricultural land as fertilizer. The use of poultry feed additives containing arsenic (As) is of particular concern in the Shenandoah River watershed (Virginia, USA), an agricultural landscape with a high density of poultry operations. This study investigated the relationship between watershed characteristics of Shenandoah River tributaries and trace element concentrations in streambed sediment and tissue of resident mollusks, including: Asian clams (Corbicula fluminea), which are commonly used biomonitors, and pleurocerid snails (Leptoxis carinata), which are generally understudied. Results failed to support the primary hypothesis of a predictive relationship between watershed densities of poultry operations and As concentrations in sediment and mollusk tissue. However, there were statistical relationships between land use in tributary watersheds and other trace elements in sediment (Cu, Mn, Pb, Zn) and tissue (Cd, Hg, Pb). Principal components analysis of the sediment data suggested a possible geologic source of As at some sites. Tissue concentrations of As were significantly higher in snails than in clams, but clams accumulated higher concentrations of other trace elements (Cd, Cr, Hg, Pb, Se). Snails may be useful biomonitors of environmental As, but appear to be less suitable than clams for studies of landscape sources of other trace elements. PMID:21713480

  11. AMS-dated mollusks in beach ridges and berms document Holocene sea-level and coastal changes in northeastern Kuwait Bay

    NASA Astrophysics Data System (ADS)

    Reinink-Smith, Linda M.

    2015-09-01

    In northeastern Kuwait, ancient beach ridges and associated berms are separated from the present shoreline by a 4-6 km-wide sabkha. A diverse mollusk fauna in the beach ridges attests to a former open marine environment. A total of 21 AMS dates were obtained in this study. Thirteen mollusk samples from beach ridges yielded AMS dates ranging from ~ 6990 cal yr BP in the southeast to ~ 3370 cal yr BP in the northwest, suggesting a southeast to northwest age progression during the Holocene transgression. In contrast, four samples from berms throughout the study area yielded AMS dates of 5195-3350 cal yr BP showing no age progression; these berms consist largely of Conomurex persicus gastropods that aggregated by storms during a highstand at ~ 5000-3500 cal yr BP. The berms are presently at ~ + 6 m above sea level, 2-3 m above the beach ridges. Human settlements were common on the ridge crests before and after the highstand. Regression to present-day sea level commenced after the highstand, which is when the sabkha began forming. A landward, marine-built terrace, which yielded AMS dates > 43,500 14C yr BP, probably formed during Marine Oxygen Isotope Stage 5e and hence is not genetically related to the beach ridges.

  12. How Are Squamous and Basal Cell Skin Cancers Diagnosed?

    MedlinePlus

    ... often enough to cure basal and squamous cell skin cancers without further treatment. There are different types of skin biopsies. The ... and Prevention Early Detection, Diagnosis, and Staging Treating Skin Cancer - ... Your Doctor After Treatment What`s New in Skin Cancer - Basal and Squamous ...

  13. The Place of Career Women in the Basals.

    ERIC Educational Resources Information Center

    Leondis, Mary T.

    A study analyzed two basal reading series to determine if they depicted realistically the role of the career woman as she exists in society. A list of female careers in the 1989 editions of Houghton-Mifflin and McGraw Hill reading basals for grades 1 to 6 was compared to the career categories of the "United States Bureau of Census, Statistical…

  14. Mineralizing angiopathy with basal ganglia stroke in an infant

    PubMed Central

    Jain, Puneet; Kishore, Praveen; Bhasin, Jasjit Singh; Arya, Subhash Chand

    2015-01-01

    Basal ganglia stroke is known following trivial head trauma. Recently a distinct clinic-radiological entity termed ‘mineralizing angiopathy’ was described. We report an infant who developed basal ganglia stroke following trivial fall. His clinic-radiological features are described. PMID:26019426

  15. How are Senior Citizens Portrayed in Basal Readers?

    ERIC Educational Resources Information Center

    Rosen, Doris F.

    Five commonly used basal readers from grades one through three were studied to determine how they portrayed and represented older adults. It was hypothesized that older adults would be portrayed as active, contributing, and productive members of society and that they would be represented in the basals in proportion to their numbers in the…

  16. Paleozoic mollusk: Hyolithes

    USGS Publications Warehouse

    Marek, L.; Yochelson, E.L.

    1964-01-01

    An unusually well-preserved Ordovician fossil from Czechoslovakia shows that the enigmatic paired structures once thought to be outgrowths of the operculum of Hyolithes are really independent structures lying between the operculumn and the aperture of the shell. The find seems to provide conclusive proof of the morphologic uniqueness of hyolithids.

  17. Giant basal cell carcinoma of the forehead: a case report.

    PubMed

    Rudić, Milan; Kranjcec, Zoran; Lisica-Sikić, Natasa; Kovacić, Marijan

    2012-03-01

    Giant basal cell carcinoma (GBCC) is defined as a tumor 5cm or greater in diameter. They present less than 1% of all basal cell carcinomas. We present a case of an 85-year-old male patient with a giant ulcerating tumor of the left forehead (measuring 7x6 cm). Under local anesthesia tumor was surgically excised. No involvement of the underlying periostal or bone structure was noted. Pathohystological exam revealed the giant basal cell carcinoma, with free surgical margins. Giant basal cell carcinomas are rare tumors and are usually result of a long duration and patient neglect. In comparison to the ordinary basal cell carcinoma these tumors have a higher metastatic potential. Surgical resection with negative surgical margin is the best possible treatment option. PMID:22816239

  18. Relationships of Bexar shale, Hensel sandstone, and Hensel dolomite (basal upper Trinity, Comanchean Cretaceous) in south-central Texas

    SciTech Connect

    Amsbury, D.L.

    1984-04-01

    The Bexar Shale has been considered the offshore equivalent of the Cow Creek Limestone, the overlying Hensel sandstone, or of the disconformity between them in outcropping sections. Cores and outcrops in Comal, Kendall, and northern Bexar Counties preserve calcitic and dolomitic caliche in the top of the Cow Creek Limestone. Above the caliche is 8-16 m(25-50 ft) of laminated or bioturbated, dolomitic siltstone and silty dolomite (Hensel dolomite). Dolomite is euhedral and silt-sized. The lower part contains collophane grains and oyster shells replaced partly by chalcedony. Carbonate grains within the upper part include angular and well-rounded mollusk and echinoid fragments; many are pyritic and coated by glauconite. Terrigenous grains in Hensel dolomite grade upward from silt to coarse subarkose sand from central Texas. In southern Bexar County, about 35 m (115 ft) of silt-, clay-, and calcite-mudstone referable to the Bexar Shale sharply overlie shallow marine Cow Creek Limestone, and grade abruptly upward into about 7 m (23 ft) of Hensel dolomite. Dolomite is overlain by calcarenite of the Glen Rose Formation containing subarkose sand grains. Similar distinctive sand grains occur in well cuttings of basal Glen Rose beds northeastward through Travis County. The Bexar represents a flood of clay-sized sediment from a distant source, spread across the San Marcos arch during a rapid transgression. Slightly younger sand, silt, and local clay of the Hensel sandstone were eroded from central Texas by a few flash floods during a major period of caliche formation in the area.

  19. Basal slip and mechanical anisotropy of biotite

    SciTech Connect

    Kronenberg, A.K. ); Kirby, S.H.; Pinkston, J. )

    1990-11-10

    The basal slip systems of biotite and their mechanical expressions have been investigated by shortening single crystals oriented to maximize and minimize shear stresses on (001). Samples loaded at 45{degree} to (001) exhibit gentle external rotations associated with dislocation glide. Samples shortened perpendicular to (001) show no evidence of nonbasal slip and fail by fracture over all conditions tested. The mechanical response of biotite shortened at 45{degree} to (001) is nearly perfectly elastic-plastic; stress-strain curves are characterized by a steep elastic slope, a sharply defined yield point, and continued deformation at low (mostly < 100 MPa), relatively constant stresses at strains >1%. Stresses measured beyond the yield point are insensitive to confining pressure over the range 200 to 500 MPa and exhibit weak dependencies upon strain rate and temperature. Assuming an exponential relationship between differential stress {sigma}{sub d} and strain rate {epsilon} = C exp({minus}Q/RT), the data collected over strain rates and temperatures of 10-7 to 10-4 s-1 and 20 to 400C, respectively, are best fit by an exponential constant {alpha} of 0.41 {plus minus} 0.08 MPa{minus}1 and an activation energy Q of 82 {plus minus} 13 kJ/mol. A power law fits the data equally well with n = 18 {plus minus} 4 and Q = 51 {plus minus} 9 kJ/mol. The strength of biotite shortened perpendicular to (001) exceeds that measured parallel to (001) and is pressure dependent. Application of the results to deformation within the continental crust suggests that biotite oriented favorably for slip is much weaker than most silicates over a wide range of geologic conditions. Its presence within foliated rocks and shear zones may limit locally the stresses that can be supported.

  20. Analysis of Basal Plane Bending and Basal Plane Dislocations in 4H-SiC Single Crystals

    NASA Astrophysics Data System (ADS)

    Ohtani, Noboru; Katsuno, Masakazu; Fujimoto, Tatsuo; Nakabayashi, Masashi; Tsuge, Hiroshi; Yashiro, Hirokatsu; Aigo, Takashi; Hirano, Hosei; Hoshino, Taizo; Ohashi, Wataru

    2009-06-01

    4H-SiC single crystals were grown by the physical vapor transport (PVT) growth method under different thermoelastic stress conditions, and the degree of basal plane bending in the crystals was characterized by the peak shift measurement of X-ray rocking curves. The results indicate that the degree of basal plane bending largely depends on the magnitude of the thermoelastic stresses imposed on the crystals during PVT growth. Quantitative analysis of basal plane bending revealed that the density of basal plane dislocations (BPDs) estimated from basal plane bending is much smaller than that obtained from defect-selective etching. It was also found that the BPD density is correlated with the threading screw dislocation (TSD) density in PVT-grown SiC crystals. These aspects of BPDs were discussed in terms of the BPD multiplication process triggered by the intersection of BPDs with a forest of TSDs extending along the c-axis.

  1. Limbal Basal Cell Density Decreases in Limbal Stem Cell Deficiency

    PubMed Central

    Chan, Eric H; Chen, Luxia; Rao, Jian Yu; Yu, Fei; Deng, Sophie X.

    2016-01-01

    Purpose To investigate changes in limbal basal epithelial cell density in eyes with limbal stem cell deficiency (LSCD) using in vivo confocal laser scanning microscopy Design retrospective observational comparative study Methods A total of 43 eyes of 30 patients diagnosed with LSCD were included in the study. Ten eyes from normal subjects were included as control. Confocal imaging of the central cornea, and the superior, nasal, inferior and temporal limbus were collected using the Heidelberg Retina Tomograph III Rostock Corneal Module. Basal cell density in all locations was measured by two independent observers. Results The mean basal cell density of the normal group was 9264 ±598 cells/mm2 in the cornea and 7120 ±362 cells/mm2 in the limbus. In the LSCD group, the mean basal cell density in the cornea decreased 31.0% (6389 ±1820 cells/mm2, p<0.001) and in the limbus decreased 23.6% (5440 ±1123 cells/mm2, p<0.001) compared to that in the control. There was a trend of basal cell density decline in more advanced stage of LSCD. The basal cell density declined in the unaffected regions at a similar degree as that in the affected region in sectoral LSCD (p>0.05). The basal cell diameter increased by 24.6% in the cornea (14.7 μm) and by 15.7% in the limbus (15.5 μm) compared to the control. Conclusions Basal cell density in both central cornea and limbus decreases in LSCD. LSCs are affected globally and basal cell density could be used as a parameter to measure LSC function at the early stages of the disease process. PMID:26149968

  2. The expanding universe of disorders of the basal ganglia.

    PubMed

    Obeso, Jose A; Rodriguez-Oroz, Maria C; Stamelou, Maria; Bhatia, Kailash P; Burn, David J

    2014-08-01

    The basal ganglia were originally thought to be associated purely with motor control. However, dysfunction and pathology of different regions and circuits are now known to give rise to many clinical manifestations beyond the association of basal ganglia dysfunction with movement disorders. Moreover, disorders that were thought to be caused by dysfunction of the basal ganglia only, such as Parkinson's disease and Huntington's disease, have diverse abnormalities distributed not only in the brain but also in the peripheral and autonomic nervous systems; this knowledge poses new questions and challenges. We discuss advances and the unanswered questions, and ways in which progress might be made. PMID:24954674

  3. Cortico-Basal Ganglia Circuit Function in Psychiatric Disease.

    PubMed

    Gunaydin, Lisa A; Kreitzer, Anatol C

    2016-01-01

    Circuit dysfunction models of psychiatric disease posit that pathological behavior results from abnormal patterns of electrical activity in specific cells and circuits in the brain. Many psychiatric disorders are associated with abnormal activity in the prefrontal cortex and in the basal ganglia, a set of subcortical nuclei implicated in cognitive and motor control. Here we discuss the role of the basal ganglia and connected prefrontal regions in the etiology and treatment of obsessive-compulsive disorder, anxiety, and depression, emphasizing mechanistic work in rodent behavioral models to dissect causal cortico-basal ganglia circuits underlying discrete behavioral symptom domains relevant to these complex disorders. PMID:26667072

  4. The basal ganglia-circa 1982 - A review and commentary

    NASA Technical Reports Server (NTRS)

    Mehler, W. R.

    1981-01-01

    A review is presented of recent studies which utilize new anterograde and retrograde axon transport methods in order to improve knowledge of the projection of the basal ganglia and to clarify their sites of origin. These studies have thrown new light on certain topographic connectional relationships and have revealed several new reciprocal connections between constituent nuclei of the basal ganglia. Also examined are the many new histochemical techniques that are now providing regional biochemical overlays for connectional maps of the central nervous system, especially regions in or interconnecting with the basal ganglia.

  5. Matrix solid-phase dispersion combined with gas chromatography-mass spectrometry for the determination of fifteen halogenated flame retardants in mollusks.

    PubMed

    Villaverde-de-Sáa, Eugenia; Valls-Cantenys, Carme; Quintana, José Benito; Rodil, Rosario; Cela, Rafael

    2013-07-26

    This study presents the development and validation of a new analytical method for the simultaneous determination of fifteen analytes classified as halogenated flame retardants (HFRs) - nine brominated diphenyl ethers (BDEs) and six novel HFRs - in different kinds of mollusks using matrix solid-phase dispersion (MSPD) followed by gas chromatography coupled to negative chemical ionization-mass spectrometry (GC-NCI-MS). The proposed method is the first one developed for such a broad range of HFRs in aquatic biota, featuring several advantages, including low solvent and sample intake, simplicity of operation, reduced cost and integration of extraction and clean-up into a single step. Under optimal conditions, 0.5g of freeze-dried sample, 0.5g of a primary-secondary amine (PSA) as solid support, a sorbent combination of 1.75g of florisil (deactivated with 5% Milli-Q water), 1.75g of acidified silica (10% (w/w) H2SO4) and 0.5g of silica, and 10mL dichloromethane as elution solvent were used. Standard addition over the extract was required however for the correct quantification due to matrix effects in the GC system, particularly for novel HFRs, that could not be compensated with the internal standards. The method afforded LODs in the range of 0.003-0.07ngg(-1) dry weight (0.0006-0.014ngg(-1) on a wet weight basis, assuming an 80% sample water content), except for decabromodiphenyl ethane (DBDPE) (0.6ngg(-1) dry weight, 0.12ngg(-1) wet weight). The accuracy of the method was evaluated with three different types of spiked mollusk species using surrogate standards and standard addition over the extract for quantification and the recoveries were in the 70-120% range, except for bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (DEHTBP) in clam (Ruditapes philippinarum) samples (46% recovery). Moreover, the method was successfully validated with standard reference materials (SRMs) of salmon and mussel tissues for BDEs. Finally, the method was applied to the determination of HFRs

  6. A psittacosaurid-like basal neoceratopsian from the Upper Cretaceous of central China and its implications for basal ceratopsian evolution.

    PubMed

    Zheng, Wenjie; Jin, Xingsheng; Xu, Xing

    2015-01-01

    Psittacosauridae (parrot-beaked dinosaurs) represents the first major radiation of ceratopsians (horned dinosaurs). However, psittacosaurids are divergent from the general morphology found in other ceratopsians, and this has resulted in their uncertain systematic position among ceratopsians. Here we describe a new basal neoceratopsian dinosaur, Mosaiceratops azumai gen. et sp. nov. based on a partial semi-articulated skeleton recovered from the Upper Cretaceous Xiaguan Formation of Neixiang County, Henan Province, China. Although our phylogenetic analysis supports this taxon as the most basal neoceratopsian, Mosaiceratops exhibits many features previously considered unique to the Psittacosauridae among the basal Ceratopsia. These include a relatively highly positioned external naris, a proportionally large premaxilla, the nasal extending ventral to the external naris, slender postorbital and temporal bars, a large notch between the basal tubera, and the edentulous premaxilla. Thus, the discovery of Mosaiceratops reduces the morphological disparity between the Psittacosauridae and other basal ceratopsians. Character optimization suggests that basal neoceratopsians have re-evolved premaxillary teeth; a major reversal previously unknown in any dinosaur clade. The new specimen also highlights the mosaic nature of evolution among early ceratopsians and supports the phylogenetic hypothesis that the Psittacosauridae is a relatively derived clade, rather than the most basal group of the Ceratopsia. PMID:26388024

  7. [Extensive basal cell cancer of the scalp - case reports].

    PubMed

    Olędzki, Szymon; Modrzejewski, Andrzej; Department Of Surgery And Emergency Nursing Pomeranian Medical University In Szczecin Poland, Ryszard

    2016-07-01

    Basal-cell canceris a slow growing, rarely metastasizes, locally malignant skin cancer. Patients with this neoplasm usually have excellent prognosis. Potentially, in some cases, a good prognosis cause a delay in therapy. Delay or withdrawal from treatment might lead to higher local extension of tumour with the destruction of the surrounding tissue. In this article we are presenting two patients with extensive basal cell cancer. The first patient underwent plastic surgery for extensive basal-cell carcinoma located in the parietal and temporal area. The second patient was observed due to recurrence of extensive basal cell carcinoma in the parietal region. Local advancement of the primary tumor could be a reason for the lack of radicality of surgery. Such advancement is rarely seen nowadays. The cases demonstrate the need for awareness about the possible severe course of the disease. PMID:27590651

  8. [Extensive basal cell cancer of the scalp - case reports].

    PubMed

    Olędzki, Szymon; Modrzejewski, Andrzej; Department Of Surgery And Emergency Nursing Pomeranian Medical University In Szczecin Poland, Ryszard

    2016-08-01

    Basal-cell canceris a slow growing, rarely metastasizes, locally malignant skin cancer. Patients with this neoplasm usually have excellent prognosis. Potentially, in some cases, a good prognosis cause a delay in therapy. Delay or withdrawal from treatment might lead to higher local extension of tumour with the destruction of the surrounding tissue. In this article we are presenting two patients with extensive basal cell cancer. The first patient underwent plastic surgery for extensive basal-cell carcinoma located in the parietal and temporal area. The second patient was observed due to recurrence of extensive basal cell carcinoma in the parietal region. Local advancement of the primary tumor could be a reason for the lack of radicality of surgery. Such advancement is rarely seen nowadays. The cases demonstrate the need for awareness about the possible severe course of the disease. PMID:27591446

  9. Short latency cerebellar modulation of the basal ganglia

    PubMed Central

    Chen, Christopher H.; Fremont, Rachel; Arteaga-Bracho, Eduardo E.; Khodakhah, Kamran

    2014-01-01

    The graceful, purposeful motion of our body is an engineering feat which remains unparalleled in robotic devices using advanced artificial intelligence. Much of the information required for complex movements is generated by the cerebellum and the basal ganglia in conjunction with the cortex. Cerebellum and basal ganglia have been thought to communicate with each other only through slow multi-synaptic cortical loops, begging the question as to how they coordinate their outputs in real time. Here we show in mice that the cerebellum rapidly modulates the activity of the striatum via a disynaptic pathway. Under physiological conditions this short latency pathway is capable of facilitating optimal motor control by allowing the basal ganglia to incorporate time-sensitive cerebellar information and by guiding the sign of cortico-striatal plasticity. Conversely, under pathological condition this pathway relays aberrant cerebellar activity to the basal ganglia to cause dystonia. PMID:25402853

  10. Origin of basal activity in mammalian olfactory receptor neurons

    PubMed Central

    2010-01-01

    Mammalian odorant receptors form a large, diverse group of G protein–coupled receptors that determine the sensitivity and response profile of olfactory receptor neurons. But little is known if odorant receptors control basal and also stimulus-induced cellular properties of olfactory receptor neurons other than ligand specificity. This study demonstrates that different odorant receptors have varying degrees of basal activity, which drives concomitant receptor current fluctuations and basal action potential firing. This basal activity can be suppressed by odorants functioning as inverse agonists. Furthermore, odorant-stimulated olfactory receptor neurons expressing different odorant receptors can have strikingly different response patterns in the later phases of prolonged stimulation. Thus, the influence of odorant receptor choice on response characteristics is much more complex than previously thought, which has important consequences on odor coding and odor information transfer to the brain. PMID:20974772

  11. Genetics Home Reference: familial idiopathic basal ganglia calcification

    MedlinePlus

    ... in regulating phosphate levels within the body (phosphate homeostasis) by transporting phosphate across cell membranes. The SLC20A2 ... link familial idiopathic basal ganglia calcification with phosphate homeostasis. Nat Genet. 2012 Feb 12;44(3):254- ...

  12. Nuclear morphometry and chromatin textural characteristics of basal cell carcinoma*

    PubMed Central

    Mendaçolli, Paola Jung; Brianezi, Gabrielli; Schmitt, Juliano Vilaverde; Marques, Mariângela Esther Alencar; Miot, Hélio Amante

    2015-01-01

    Histological subtypes of basal cell carcinoma have biological, evolutionary and distinct prognostic behavior. The analysis of characteristics of the nucleus can provide data on their cellular physiology and behavior. The authors of this study evaluated nuclear morphological parameters and textural patterns of chromatin from different subtypes of basal cell carcinoma: nodular (n=37), superficial (n=28) and sclerodermiform (n=28). The parameters were compared between neoplasms' subtypes and with unaffected adjacent basal epithelium. Nuclear area and diameter of sclerodermiform neoplasms were superior to the other subtypes. Chromatin's color intensity and fractal dimension were less intense in superficial subtypes. Nuclear roundness and chromatin's entropy presented lower values in tumors than in normal epithelium. There was significant correlation between morphological and textural variables of normal skin and tumors. Morphometric elements and textural chromatin's homogeneity of basal cell carcinomas may be related to evolutionary, biological and behavior particularities related to each histotype. PMID:26734870

  13. Short latency cerebellar modulation of the basal ganglia.

    PubMed

    Chen, Christopher H; Fremont, Rachel; Arteaga-Bracho, Eduardo E; Khodakhah, Kamran

    2014-12-01

    The graceful, purposeful motion of our body is an engineering feat that remains unparalleled in robotic devices using advanced artificial intelligence. Much of the information required for complex movements is generated by the cerebellum and the basal ganglia in conjunction with the cortex. Cerebellum and basal ganglia have been thought to communicate with each other only through slow, multi-synaptic cortical loops, begging the question as to how they coordinate their outputs in real time. We found that the cerebellum rapidly modulates the activity of the striatum via a disynaptic pathway in mice. Under physiological conditions, this short latency pathway was capable of facilitating optimal motor control by allowing the basal ganglia to incorporate time-sensitive cerebellar information and by guiding the sign of cortico-striatal plasticity. Conversely, under pathological condition, this pathway relayed aberrant cerebellar activity to the basal ganglia to cause dystonia. PMID:25402853

  14. PERIANAL BASAL CELL CARCINOMA—AN UNUSUAL SITE OF OCCURRENCE

    PubMed Central

    Nagendra Naidu, D V; Rajakumar, V

    2010-01-01

    Basal cell carcinoma is the most common nonmelanoma skin cancer. Its occurrence in the perianal region is very rare. Awareness of its benign behavior in this region, in contrast to the earlier reports, is vital in its management. Local excision seems to provide adequate control. We are herewith reporting an extremely rare case of a 69-year-old male with basal cell carcinoma treated adequately with local excision. PMID:20606890

  15. Cognitive-motor interactions of the basal ganglia in development

    PubMed Central

    Leisman, Gerry; Braun-Benjamin, Orit; Melillo, Robert

    2014-01-01

    Neural circuits linking activity in anatomically segregated populations of neurons in subcortical structures and the neocortex throughout the human brain regulate complex behaviors such as walking, talking, language comprehension, and other cognitive functions associated with frontal lobes. The basal ganglia, which regulate motor control, are also crucial elements in the circuits that confer human reasoning and adaptive function. The basal ganglia are key elements in the control of reward-based learning, sequencing, discrete elements that constitute a complete motor act, and cognitive function. Imaging studies of intact human subjects and electrophysiologic and tracer studies of the brains and behavior of other species confirm these findings. We know that the relation between the basal ganglia and the cerebral cortical region allows for connections organized into discrete circuits. Rather than serving as a means for widespread cortical areas to gain access to the motor system, these loops reciprocally interconnect a large and diverse set of cerebral cortical areas with the basal ganglia. Neuronal activity within the basal ganglia associated with motor areas of the cerebral cortex is highly correlated with parameters of movement. Neuronal activity within the basal ganglia and cerebellar loops associated with the prefrontal cortex is related to the aspects of cognitive function. Thus, individual loops appear to be involved in distinct behavioral functions. Damage to the basal ganglia of circuits with motor areas of the cortex leads to motor symptoms, whereas damage to the subcortical components of circuits with non-motor areas of the cortex causes higher-order deficits. In this report, we review some of the anatomic, physiologic, and behavioral findings that have contributed to a reappraisal of function concerning the basal ganglia and cerebellar loops with the cerebral cortex and apply it in clinical applications to attention deficit/hyperactivity disorder (ADHD

  16. Basal Dynamics and Internal Structure of Ice Sheets

    NASA Astrophysics Data System (ADS)

    Wolovick, Michael J.

    The internal structure of ice sheets reflects the history of flow and deformation experienced by the ice mass. Flow and deformation are controlled by processes occurring within the ice mass and at its boundaries, including surface accumulation or ablation, ice rheology, basal topography, basal sliding, and basal melting or freezing. The internal structure and basal environment of ice sheets is studied with ice-penetrating radar. Recently, radar observations in Greenland and Antarctica have imaged large englacial structures rising from near the bed that deform the overlying stratigraphy into anticlines, synclines, and overturned folds. The mechanisms that may produce these structures include basal freeze-on, travelling slippery patches at the ice base, and rheological contrasts within the ice column. In this thesis, I explore the setting and mechanisms that produce large basal stratigraphic structures inside ice sheets. First, I use radar data to map subglacial hydrologic networks that deliver meltwater uphill towards freeze-on structures in East Antarctica. Next, I use a thermomechanical flowline model to demonstrate that trains of alternating slippery and sticky patches can form underneath ice sheets and travel downstream over time. The disturbances to the ice flow field produced by these travelling patches produce stratigraphic folds resembling the observations. I then examine the overturned folds produced by a single travelling sticky patch using a kinematic flowline model. This model is used to interpret stratigraphic measurements in terms of the dynamic properties of basal slip. Finally, I use a simple local one-dimensional model to estimate the thickness of basal freeze-on that can be produced based on the supply of available meltwater, the thermal boundary conditions, ice sheet geometry, and the ice flow regime.

  17. The relation between dermoscopy and histopathology of basal cell carcinoma*

    PubMed Central

    Emiroglu, Nazan; Cengiz, Fatma Pelin; Kemeriz, Funda

    2015-01-01

    BACKGROUND: Basal cell carcinoma is the most frequent cancer in fair-skinned populations and dermoscopy is an important, non-invasive technique that aids in the diagnosis of Basal cell carcinoma. OBJECTIVES: The aim of this study was to evaluate the relationship between histopathological subtypes and dermoscopic features of Basal cell carcinoma. METHODS: This study included 98 patients with clinically and histopathologically confirmed Basal cell carcinomas. The dermoscopic features of the lesions from each patient were analyzed before the histopathological findings were evaluated. RESULTS: Dermoscopic structures were observed in all 98 patients and irregular vascularity was identified in 78 patients (79.6%). The most common vascular pattern was the presence of arborizing vessels (42 patients, 42.9%) followed by arborizing microvessels (21 patients, 21.4%) and short fine telangiectasias (SFTs; 15 patients, 15.3%). White streaks (38 patients, 38.8%), translucency (31 patients, 31.6%), a milky-pink to red background (42 patients, 42.9%), and erosion/ulceration (29 patients, 29.6%) were also observed. Pigmented islands were seen as blue-gray globules (7 patients, 7.1%) and blue-gray ovoid nests (42 patients, 42.9%). The pigment distribution pattern was maple leaf-like areas in 9 patients (9.2 %) and spoke wheel-like areas in 6 patients (6.1%). CONCLUSIONS: Basal cell carcinomas show a wide spectrum of dermoscopic features. Arborizing vessels were the most common dermoscopic findings in Basal cell carcinomas, while superficial Basal cell carcinomas displayed mainly milky-pink to red areas, and arborizing microvessels. The most common dermoscopic features of pigmented types were islands of pigment (blue-gray globules, blue-gray ovoid nests). In conclusion, dermoscopy can be used as a valuable tool for the diagnosis of Basal cell carcinomas and prediction of their histopathological subtypes. PMID:26131865

  18. Disruption of automatic speech following a right basal ganglia lesion.

    PubMed

    Speedie, L J; Wertman, E; Ta'ir, J; Heilman, K M

    1993-09-01

    Following a right basal ganglia lesion, a right-handed man, age 75, was unable to recite familiar verses. Serial automatic speech, singing, recitation of rhymes, and swearing were impaired, and only idioms and social greetings were preserved. Speech no longer contained overused phrases and he could comprehend automatic speech. In contrast, propositional speech was preserved in both French and Hebrew. Right basal ganglia lesions may impair production but not comprehension of automatic speech. PMID:8414029

  19. Challenges to the Application of δ15N measurements of the organic fraction of archaeological and fossil mollusk shells to assess paleoenvironmental change.

    NASA Astrophysics Data System (ADS)

    Andrus, C. F. T.

    2015-12-01

    Nitrogen isotope analysis of the organic fraction of mollusk shells is beginning to be applied to questions of past anthropogenic and natural environmental variation using samples from archaeological and fossil deposits. Fairly extensive proxy validation research has been conducted in the past decade, documenting the relationship between the δ15N of ambient particulate organic matter, mollusk soft tissues, and shell organic matrix. However, comparatively little research has addressed the potential effects of taphonomy and diagenesis on these proxy records. Assessing archaeological samples are especially complex in that humans may have transported and/or cooked shell prior to deposition. Shell δ15N data will be presented from modern and archaeological oyster (Crassostrea virginica) and clam shell (Mercenaria spp.) of various late Holocene ages and late Cretaceous Crassatellites vadosus shells. Archaeological shells show some loss of organic matter over time, yet some Cretaceous shells retain enough matrix to permit δ15N analysis. The Cretaceous samples required concentration of the remaining organic matrix by removing carbonate via acid pretreatment prior to EA-IRMS analysis, but modern and archaeological shells had sufficient organic matrix to permit analysis without acid pretreatment. The δ15N data from the archaeological shells do not display obvious alteration from the loss of organic matrix. The results of cooking experiments performed on modern oyster shells also indicate little alteration of δ15N values, unless the shell was heated to the point of disintegration. While these experiments indicate promise for the application of δ15N analysis of shell organic matter, the results are incomplete and lack ideal control over initial δ15N values in ancient samples used for comparisons. Future research, perhaps focused on compound-specific δ15N analysis and additional controlled experiments on moderns shells, may improve this assessment.

  20. Matrix solid-phase dispersion combined to liquid chromatography-tandem mass spectrometry for the determination of paraben preservatives in mollusks.

    PubMed

    Villaverde-de-Sáa, Eugenia; Rodil, Rosario; Quintana, José Benito; Cela, Rafael

    2016-08-12

    A method for the extraction and determination of seven parabens, esters of 4-hydroxybenzoic acid, widely used as preservatives in personal care products, pharmaceuticals, etc., and two chlorinated derivatives (mono- and di-chloro methyl paraben) from mollusk samples was developed by combining matrix solid-phase dispersion (MSPD) and liquid chromatography-tandem mass spectrometry. MSPD parameters, such as solvent, solid support and clean-up sorbent, were optimized. Besides, since blank problems were observed for some parabens, these were investigated and blanks were tackled by precleaning all sorbents prior to use. Under final conditions, 0.5g of freeze-dried mollusk were dispersed with 1.2g of silica and packed into a cartridge containing 3g of C18, as on-line clean-up sorbent. This cartridge was eluted with 10mL of acetonitrile, evaporated and reconstituted in methanol for analysis. In the validation stage, successful linearity (R(2)>0.999), recoveries (between 71 and 117% for most analytes), precision (RSD lower than 21%) and limits of detection and quantification (LOD and LOQ, lower than 0.4 and 1.4ngg(-1) dry weight respectively) levels were achieved. Finally, the new methodology was applied to mussel, clam and cockle samples. Methyl paraben was above the LOQ in five of the six samples (not found in one clam sample) at concentrations up to 7ngg(-1) dry weight. Ethyl paraben was found above the LOQ in mussel and cockle samples at a concentration level around 0.3ngg(-1). n-Propyl paraben was only above the LOQ in one mussel sample. PMID:27401811

  1. Classification of Cryostructures of Basal Glacier Ice Using Tomodensitometry

    NASA Astrophysics Data System (ADS)

    Fortier, D.; Kanevskiy, M.; Dillon, M.; Stephani, E.; Shur, Y.; Jorgenson, T. M.

    2008-12-01

    In permafrost areas, the extent of former glaciations can be inferred from the occurrence of buried glacier ice (Murton et al. 2005). Buried basal glacier ice can only be distinguished from other type of massive ice if the properties and structure of contemporary basal ice are well-known. Several classifications of basal ice have been developed based on the geological facies analysis (Lawson 1979, Knight 1994, Hubbard and Sharp 1995). However, none of them have addressed basal ice descriptions in terms of cryostructures. We used conventional field descriptions and microcomputed tomodensitometry to evaluate structure and properties of sediments including basal ice. The scan images were processed using a thresholding technique which assigns gray scale values to the components of basal ice based on their density. These values were used to determine the volumetric content of each component (ice, sediment, gas). We have used the Mathworks MATLAB R2007a software to produce three-dimensional images of basal ice cryostructures. The main advantage of these is to obtain in a non-destructive manner precise average ice and sediment contents for a given volume of a particular cryostructure. These models allow for a detailed 3D visualization of the cryostructures which is a powerful tool to study their architecture and the geometric relations between ice and sediments. The technical details of these operations have been presented by Dillon et al. (2008). Our cryostructures classification of basal glacier ice and sediments includes seven types of cryostructures observed in the basal ice of the Matanuska Glacier: (1) Porous; (2) Crustal; (3) Reticulate; (4) Lenticular; (5) Layered; (6) Suspended (includes four sub-types: Suspended dispersed, Micro-suspended, Suspended- intergranular, Suspended inter-crystalline); (7) Massive ice. The classification is illustrated by detailed photographs, sketches and bi-dimensional (2D) scan images of the various cryostructures along with their

  2. Basal ganglia output reflects internally-specified movements

    PubMed Central

    Lintz, Mario J; Felsen, Gidon

    2016-01-01

    How movements are selected is a fundamental question in systems neuroscience. While many studies have elucidated the sensorimotor transformations underlying stimulus-guided movements, less is known about how internal goals – critical drivers of goal-directed behavior – guide movements. The basal ganglia are known to bias movement selection according to value, one form of internal goal. Here, we examine whether other internal goals, in addition to value, also influence movements via the basal ganglia. We designed a novel task for mice that dissociated equally rewarded internally-specified and stimulus-guided movements, allowing us to test how each engaged the basal ganglia. We found that activity in the substantia nigra pars reticulata, a basal ganglia output, predictably differed preceding internally-specified and stimulus-guided movements. Incorporating these results into a simple model suggests that internally-specified movements may be facilitated relative to stimulus-guided movements by basal ganglia processing. DOI: http://dx.doi.org/10.7554/eLife.13833.001 PMID:27377356

  3. Dopamine-glutamate interactions in the basal ganglia.

    PubMed

    Schmidt, W J

    1998-01-01

    In an attempt to formulate a working hypothesis of basal-ganglia functions, arguments are considered suggesting that the basal ganglia are involved in a process of response selection i.e. in the facilitation of "wanted" and in the suppression of "unwanted" behaviour. The meso-accumbal dopamine-system is considered to mediate natural and drug-induced reward and sensitization. The meso-striatal dopamine-system seems to fulfill similar functions: It may mediate reinforcement which strengthens a given behaviour when elicited subsequently, but which is not experienced as reward or hedonia. Glutamate as the transmitter of the corticofugal projections to the basal ganglia nuclei and of the subthalamic neurons is critically involved in basal ganglia functions and dysfunctions; for example Parkinson's disease can be considered to be a secondary hyperglutamatergic disease. Additionally, glutamate is an essential factor in the plasticity response of the basal-ganglia. However, opposite to previous suggestions, the NMDA-receptor blocker MK-801 does not prevent psychostimulant- nor morphine-induced day to day increase (sensitization) of locomotion. Also the day to day increase of haloperidol-induced catalepsy was not prevented by MK-801. PMID:9871434

  4. Phylogeny of Basal Iguanodonts (Dinosauria: Ornithischia): An Update

    PubMed Central

    McDonald, Andrew T.

    2012-01-01

    The precise phylogenetic relationships of many non-hadrosaurid members of Iguanodontia, i.e., basal iguanodonts, have been unclear. Therefore, to investigate the global phylogeny of basal iguanodonts a comprehensive data matrix was assembled, including nearly every valid taxon of basal iguanodont. The matrix was analyzed in the program TNT, and the maximum agreement subtree of the resulting most parsimonious trees was then calculated in PAUP. Ordering certain multistate characters and omitting taxa through safe taxonomic reduction did not markedly improve resolution. The results provide some new information on the phylogeny of basal iguanodonts, pertaining especially to obscure or recently described taxa, and support some recent taxonomic revisions, such as the splitting of traditional “Camptosaurus” and “Iguanodon”. The maximum agreement subtree also shows a close relationship between the Asian Probactrosaurus gobiensis and the North American Eolambia, supporting the previous hypothesis of faunal interchange between Asia and North America in the early Late Cretaceous. Nevertheless, the phylogenetic relationships of many basal iguanodonts remain ambiguous due to the high number of taxa removed from the maximum agreement subtree and poor resolution of consensus trees. PMID:22629328

  5. Basal bodies across eukaryotes series: basal bodies in the freshwater planarian Schmidtea mediterranea.

    PubMed

    Azimzadeh, Juliette; Basquin, Cyril

    2016-01-01

    The freshwater planarian Schmidtea mediterranea has recently emerged as a valuable model system to study basal bodies (BBs) and cilia. Planarians are free-living flatworms that use cilia beating at the surface of their ventral epidermis for gliding along substrates. The ventral epidermis is composed of multiciliated cells (MCCs) that are similar to the MCCs in the respiratory airways, the brain ventricles, and the oviducts in vertebrates. In the planarian epidermis, each cell assembles approximately eighty cilia that beat in a coordinate fashion across the tissue. The BBs that nucleate these cilia all assemble de novo during terminal differentiation of MCCs. The genome of the planarian S. mediterranea has been sequenced and efficient methods for targeting gene expression by RNA interference are available. Defects induced by perturbing the expression of BB proteins can be detected simply by analyzing the locomotion of planarians. BBs are present in large numbers and in predictable orientation, which greatly facilitates analyses by immunofluorescence and electron microscopy. The great ease in targeting gene expression and analyzing associated defects allowed to identify a set of proteins required for BB assembly and function in planarian MCCs. Future technological developments, including methods for transgenic expression in planarians and in related species, will achieve turning free-living flatworms into powerful model systems to study MCCs and the associated human pathologies. PMID:26998257

  6. Prostatic inflammation enhances basal-to-luminal differentiation and accelerates initiation of prostate cancer with a basal cell origin

    PubMed Central

    Kwon, Oh-Joon; Zhang, Li; Ittmann, Michael M.; Xin, Li

    2014-01-01

    Chronic inflammation has been shown to promote the initiation and progression of diverse malignancies by inducing genetic and epigenetic alterations. In this study, we investigate an alternative mechanism through which inflammation promotes the initiation of prostate cancer. Adult murine prostate epithelia are composed predominantly of basal and luminal cells. Previous studies revealed that the two lineages are largely self-sustained when residing in their native microenvironment. To interrogate whether tissue inflammation alters the differentiation program of basal cells, we conducted lineage tracing of basal cells using a K14-CreER;mTmG model in concert with a murine model of prostatitis induced by infection from the uropathogenic bacteria CP9. We show that acute prostatitis causes tissue damage and creates a tissue microenvironment that induces the differentiation of basal cells into luminal cells, an alteration that rarely occurs under normal physiological conditions. Previously we showed that a mouse model with prostate basal cell-specific deletion of Phosphatase and tensin homolog (K14-CreER;Ptenfl/fl) develops prostate cancer with a long latency, because disease initiation in this model requires and is limited by the differentiation of transformation-resistant basal cells into transformation-competent luminal cells. Here, we show that CP9-induced prostatitis significantly accelerates the initiation of prostatic intraepithelial neoplasia in this model. Our results demonstrate that inflammation results in a tissue microenvironment that alters the normal prostate epithelial cell differentiation program and that through this cellular process inflammation accelerates the initiation of prostate cancer with a basal cell origin. PMID:24367088

  7. Time representation in reinforcement learning models of the basal ganglia

    PubMed Central

    Gershman, Samuel J.; Moustafa, Ahmed A.; Ludvig, Elliot A.

    2014-01-01

    Reinforcement learning (RL) models have been influential in understanding many aspects of basal ganglia function, from reward prediction to action selection. Time plays an important role in these models, but there is still no theoretical consensus about what kind of time representation is used by the basal ganglia. We review several theoretical accounts and their supporting evidence. We then discuss the relationship between RL models and the timing mechanisms that have been attributed to the basal ganglia. We hypothesize that a single computational system may underlie both RL and interval timing—the perception of duration in the range of seconds to hours. This hypothesis, which extends earlier models by incorporating a time-sensitive action selection mechanism, may have important implications for understanding disorders like Parkinson's disease in which both decision making and timing are impaired. PMID:24409138

  8. New therapeutic options for actinic keratosis and basal cell carcinoma.

    PubMed

    Sligh, James E

    2014-06-01

    Actinic keratosis (AK) is a common premalignant skin lesion that is frequently treated by cryosurgery. Basal cell carcinoma is the most common malignancy of man, and early-stage lesions are usually cured via surgery. Advanced basal cell carcinoma may require more extensive surgery resulting in deformity, and many advanced lesions cannot be treated surgically. Several recent developments have improved therapeutic options for both conditions. Cryosurgery is still a mainstay of treatment for AK, but the introduction of effective topical agents, imiquimod cream and ingenol mebutate, has provided alternatives to cryosurgery. For advanced basal cell carcinoma, the small-molecule inhibitor vismodegib has proven to be an effective therapy for lesions that are not amenable to surgery and has demonstrated ability to achieve dramatic improvement in advanced, potentially disfiguring cancer. PMID:25268601

  9. Deep-Brain Stimulation for Basal Ganglia Disorders

    PubMed Central

    Wichmann, Thomas; DeLong, Mahlon R.

    2011-01-01

    The realization that medications used to treat movement disorders and psychiatric conditions of basal ganglia origin have significant shortcomings, as well as advances in the understanding of the functional organization of the brain, has led to a renaissance in functional neurosurgery, and particularly the use of deep brain stimulation (DBS). Movement disorders are now routinely being treated with DBS of ‘motor’ portions of the basal ganglia output nuclei, specifically the subthalamic nucleus and the internal pallidal segment. These procedures are highly effective and generally safe. Use of DBS is also being explored in the treatment of neuropsychiatric disorders, with targeting of the ‘limbic’ basal ganglia-thalamocortical circuitry. The results of these procedures are also encouraging, but many unanswered questions remain in this emerging field. This review summarizes the scientific rationale and practical aspects of using DBS for neurologic and neuropsychiatric disorders. PMID:21804953

  10. Synchronizing activity of basal ganglia and pathophysiology of Parkinson's disease.

    PubMed

    Heimer, G; Rivlin, M; Israel, Z; Bergman, H

    2006-01-01

    Early physiological studies emphasized changes in the discharge rate of basal ganglia in the pathophysiology of Parkinson's disease (PD), whereas recent studies stressed the role of the abnormal oscillatory activity and neuronal synchronization of pallidal cells. However, human observations cast doubt on the synchronization hypothesis since increased synchronization may be an epi-phenomenon of the tremor or of independent oscillators with similar frequency. Here, we show that modern actor/ critic models of the basal ganglia predict the emergence of synchronized activity in PD and that significant non-oscillatory and oscillatory correlations are found in MPTP primates. We conclude that the normal fluctuation of basal ganglia dopamine levels combined with local cortico-striatal learning rules lead to noncorrelated activity in the pallidum. Dopamine depletion, as in PD, results in correlated pallidal activity, and reduced information capacity. We therefore suggest that future deep brain stimulation (DBS) algorithms may be improved by desynchronizing pallidal activity. PMID:17017503

  11. Oscillations and the basal ganglia: Motor control and beyond

    PubMed Central

    Brittain, John-Stuart; Brown, Peter

    2016-01-01

    Oscillations form a ubiquitous feature of the central nervous system. Evidence is accruing from cortical and sub-cortical recordings that these rhythms may be functionally important, although the precise details of their roles remain unclear. The basal ganglia share this predilection for rhythmic activity which, as we see in Parkinson’s disease, becomes further enhanced in the dopamine depleted state. While certain cortical rhythms appear to penetrate the basal ganglia, others are transformed or blocked. Here, we discuss the functional association of oscillations in the basal ganglia and their relationship with cortical activity. We further explore the neural underpinnings of such oscillatory activity, including the important balance to be struck between facilitating information transmission and limiting information coding capacity. Finally, we introduce the notion that synchronised oscillatory activity can be broadly categorised as immutability promoting rhythms that reinforce incumbent processes, and mutability promoting rhythms that favour novel processing. PMID:23711535

  12. BASAL GANGLIA PATHOLOGY IN SCHIZOPHRENIA: DOPAMINE CONNECTIONS and ANOMALIES

    PubMed Central

    Perez-Costas, Emma; Melendez-Ferro, Miguel; Roberts, Rosalinda C.

    2010-01-01

    Schizophrenia is a severe mental illness that affects 1% of the world population. The disease usually manifests itself in early adulthood with hallucinations, delusions, cognitive and emotional disturbances and disorganized thought and behavior. Dopamine was the first neurotransmitter to be implicated in the disease, and though no longer the only suspect in schizophrenia pathophysiology, it obviously plays an important role. The basal ganglia are the site of most of the dopamine neurons in the brain and the target of antipsychotic drugs. In this review we will start with an overview of basal ganglia anatomy emphasizing dopamine circuitry. Then, we will review the major deficits in dopamine function in schizophrenia, emphasizing the role of excessive dopamine in the basal ganglia and the link to psychosis. PMID:20089137

  13. Removal of craniopharyngioma via fronto-basal interhemispheric approach

    PubMed Central

    XING, HONGSHUN; XING, HONGBO; HUI, PEIQUAN; YANG, BIN

    2016-01-01

    The effectiveness and safety of fronto-basal interhemispheric approach in treating craniopharyngioma were evaluated. In this retrospective study, the safety and effectiveness of fronto-basal interhemispheric approach for surgical resection of craniopharyngioma in 20 patients was analyzed. Of the 20 patients, 12 were men and 8 were women, aged 15–65 years, with an average age of 42.5 years. The course of disease ranged from 1 to 36 months. The craniopharyngioma tumor was completely removed through surgical resection in 18 patients (90%) and partially removed in 2 patients. The pituitary stalk was preserved in 18 patients and 1 patient succumbed during the study period due to large area pulmonary embolism. In conclusion, fronto-basal interhemispheric approach provides better access to the tumor that grows in the sella-hypothalamus and anterior third ventricle region. Using this approach, tumors can be resected while preserving the vital structures such as the pituitary stalk and hypothalamus. PMID:27347116

  14. Covert skill learning in a cortical-basal ganglia circuit.

    PubMed

    Charlesworth, Jonathan D; Warren, Timothy L; Brainard, Michael S

    2012-06-14

    We learn complex skills such as speech and dance through a gradual process of trial and error. Cortical-basal ganglia circuits have an important yet unresolved function in this trial-and-error skill learning; influential 'actor-critic' models propose that basal ganglia circuits generate a variety of behaviours during training and learn to implement the successful behaviours in their repertoire. Here we show that the anterior forebrain pathway (AFP), a cortical-basal ganglia circuit, contributes to skill learning even when it does not contribute to such 'exploratory' variation in behavioural performance during training. Blocking the output of the AFP while training Bengalese finches to modify their songs prevented the gradual improvement that normally occurs in this complex skill during training. However, unblocking the output of the AFP after training caused an immediate transition from naive performance to excellent performance, indicating that the AFP covertly gained the ability to implement learned skill performance without contributing to skill practice. In contrast, inactivating the output nucleus of the AFP during training completely prevented learning, indicating that learning requires activity within the AFP during training. Our results suggest a revised model of skill learning: basal ganglia circuits can monitor the consequences of behavioural variation produced by other brain regions and then direct those brain regions to implement more successful behaviours. The ability of the AFP to identify successful performances generated by other brain regions indicates that basal ganglia circuits receive a detailed efference copy of premotor activity in those regions. The capacity of the AFP to implement successful performances that were initially produced by other brain regions indicates precise functional connections between basal ganglia circuits and the motor regions that directly control performance. PMID:22699618

  15. Cell cycle of globose basal cells in rat olfactory epithelium.

    PubMed

    Huard, J M; Schwob, J E

    1995-05-01

    The olfactory epithelium of adult mammals has the unique property of generating olfactory sensory neurons throughout life. Cells of the basal compartment, which include horizontal and globose basal cells, are responsible for the ongoing process of neurogenesis in this system. We report here that the globose basal cells in olfactory epithelium of rats, as in mice, are the predominant type of proliferating cell, and account for 97.6% of the actively dividing cells in the basal compartment of the normal epithelium. Globose basal cells have not been fully characterized in terms of their proliferative properties, and the dynamic aspects of neurogenesis are not well understood. As a consequence, it is uncertain whether cell kinetic properties are under any regulation that could affect the rate of neurogenesis. To address this gap in our knowledge, we have determined the duration of both the synthesis phase (S-phase) and the full cell cycle of globose basal cells in adult rats. The duration of the S-phase was found to be 9 hr in experiments utilizing sequential injections of either IdU followed by BrdU or 3H-thy followed by BrdU. The duration of the cell cycle was determined by varying the time interval between the injections of 3H-thy and BrdU and tracking the set of cells that exit S shortly after the first injection. With this paradigm, the interval required for these cells to traverse G2, M, G1, and a second S-phase, is equivalent to the duration of one mitotic cycle and equals 17 hr. These observations serve as the foundation to assess whether the cell cycle duration is subject to regulation in response to experimental injury, and whether such regulation is partly responsible for changes in the rate of neurogenesis in such settings. PMID:7647371

  16. Basal cell carcinomas in elderly patients treated by cryotherapy.

    PubMed

    Chiriac, Anca; Mihaila, Doina; Foia, Liliana; Solovan, Caius

    2013-01-01

    Basal cell carcinoma is a malignant skin tumor with high incidence in our country, especially in rural areas, on sun-exposed skin (particularly on the face) in elderly patients. We present three cases of basal cell carcinoma with good results with cryotherapy. This report aims to outline and to prove that in some difficult situations, a simple, inexpensive, easy-to-perform procedure with no contraindications and with minimal side effects (erythema, mild pain) can be applied and resolve such cases. PMID:23569366

  17. Basal cell carcinomas in elderly patients treated by cryotherapy

    PubMed Central

    Chiriac, Anca; Mihaila, Doina; Foia, Liliana; Solovan, Caius

    2013-01-01

    Basal cell carcinoma is a malignant skin tumor with high incidence in our country, especially in rural areas, on sun-exposed skin (particularly on the face) in elderly patients. We present three cases of basal cell carcinoma with good results with cryotherapy. This report aims to outline and to prove that in some difficult situations, a simple, inexpensive, easy-to-perform procedure with no contraindications and with minimal side effects (erythema, mild pain) can be applied and resolve such cases. PMID:23569366

  18. Production of Basal Bodies in bulk for dense multicilia formation

    PubMed Central

    Yan, Xiumin; Zhao, Huijie; Zhu, Xueliang

    2016-01-01

    Centriole number is normally under tight control and is directly linked to ciliogenesis. In cells that use centrosomes as mitotic spindle poles, one pre-existing mother centriole is allowed to duplicate only one daughter centriole per cell cycle. In multiciliated cells, however, many centrioles are generated to serve as basal bodies of the cilia. Although deuterosomes were observed more than 40 years ago using electron microscopy and are believed to produce most of the basal bodies in a mother centriole-independent manner, the underlying molecular mechanisms have remained unknown until recently. From these findings arise more questions and a call for clarifications that will require multidisciplinary efforts. PMID:27408696

  19. Radiation enhanced basal plane dislocation glide in GaN

    NASA Astrophysics Data System (ADS)

    Yakimov, Eugene B.; Vergeles, Pavel S.; Polyakov, Alexander Y.; Lee, In-Hwan; Pearton, Stephen J.

    2016-05-01

    A movement of basal plane segments of dislocations in GaN films grown by epitaxial lateral overgrowth under low energy electron beam irradiation (LEEBI) was studied by the electron beam induced current (EBIC) method. Only a small fraction of the basal plane dislocation segments were susceptible to irradiation and the movement was limited to relatively short distances. The effect is explained by the radiation enhanced dislocation glide (REDG) in the structure with strong pinning. A dislocation velocity under LEEBI with a beam current lower than 1 nA was estimated as about 10 nm/s. The results assuming the REDG for prismatic plane dislocations were presented.

  20. Basal Ganglia Plus Insula Damage Yields Stronger Disruption of Smoking Addiction Than Basal Ganglia Damage Alone

    PubMed Central

    2014-01-01

    Introduction: The main objective of this study was to elucidate the importance of the basal ganglia (BG) and insula (INS) for nicotine addiction and smoking behavior. Methods: We used a lesion study examining the effects of BG and INS damage on changes in smoking behavior and nicotine dependence over time in a prospective manner. We studied whether combined BG and INS damage yields more substantial disruption of smoking and nicotine dependence than damage to the BG alone and compared with damage to other brain regions outside the BG and INS (brain-damaged comparison [BDC] group). We obtained neuroanatomical and behavioral data for 63 neurological patients with stroke at 1 month after onset and at 3-, 6-, and 12-month follow-ups. All patients were smokers at lesion onset. Results: The BG and BG + INS groups had significantly higher and more sustained rates of smoking cessation than patients with damage elsewhere. By 12 months after onset, only 14.3% of the patients in the BDC group were classified as nonsmokers. In the BG group, 37% were not smoking by the 12-month follow-up, and in the BG + INS group, smoking cessation was even more pronounced, as 75% of this group was not smoking at the 12-month epoch. Conclusions: The findings show that damage to the BG alone can cause disruption of smoking addiction, and when BG damage is combined with INS damage, the disruption increases. The latter finding is consistent with the proposal that the INS has a key role in smoking addiction. PMID:24169814

  1. Molecular characterization of an inhibitor of NF-κB in the scallop Argopecten purpuratus: First insights into its role on antimicrobial peptide regulation in a mollusk.

    PubMed

    Oyanedel, D; Gonzalez, R; Flores-Herrera, P; Brokordt, K; Rosa, R D; Mercado, L; Schmitt, P

    2016-05-01

    Inhibitors of nuclear factor kappa B (IκBs) are major control components of the Rel/NF-κB signaling pathway, a key regulator in the modulation of the expression of immune-related genes in vertebrates and invertebrates. The activation of the Rel/NF-κB signaling pathway depends largely in the degradation of IκB proteins and thus, IκBs are a main target for the identification of genes whose expression is controlled by Rel/NF-κB pathway. In order to identify such regulation in bivalve mollusks, the cDNA sequence encoding an IκB protein was characterized in the scallop Argopecten purpuratus, ApIκB. The cDNA sequence of ApIκB is comprised of 1480 nucleotides with a 1086 bp open reading frame encoding for 362 amino acids. Bioinformatics analysis showed that ApIκB displays the conserved features of IκB proteins. The deduced amino acid sequence consists of a 39.7 kDa protein, which has an N-terminal degradation motif, six ankyrin repeats and a C-terminal phosphorylation site motif. Phylogenetic analysis revealed a high degree of identity between ApIκB and other IκBs from mollusks, but also to arthropod cactus proteins and vertebrate IκBs. Tissue expression analysis indicated that ApIκB is expressed in all examined tissues and it is upregulated in circulating hemocytes from scallops challenged with the pathogenic Gram-negative bacterium Vibrio splendidus. After inhibiting ApIκB gene expression using the RNA interference technology, the gene expression of the antimicrobial peptide big defensin was upregulated in hemocytes from non-challenged scallops. Results suggest that ApIκB may control the expression of antimicrobial effectors such as big defensin via a putative Rel/NF-κB signaling pathway. This first evidence will help to deepen the knowledge of the Rel/NF-κB conserved pathway in scallops. PMID:26993612

  2. Ultrastructure of the basal lamina of bovine ovarian follicles and its relationship to the membrana granulosa.

    PubMed

    Irving-Rodgers, H F; Rodgers, R J

    2000-03-01

    Different morphological phenotypes of follicular basal lamina and of membrana granulosa have been observed. Ten preantral follicles (< 0. 1 mm), and 17 healthy and six atretic antral follicles (0.5-12 mm in diameter) were processed for light and electron microscopy to investigate the relationship the between follicular basal lamina and membrana granulosa. Within each antral follicle, the shape of the basal cells of the membrana granulosa was uniform, and either rounded or columnar. There were equal proportions of follicles basal cells and with rounded basal cells. Larger follicles had only rounded basal cells. Conventional basal laminae of a single layer adjacent to the basal granulosa cells were observed in healthy follicles at the preantral and antral stages. However, at the preantral stage, the conventional types of basal lamina were enlarged or even partially laminated. A second type of basal lamina, described as 'loopy', occurred in about half the preantral follicles and in half the antral follicles basal laminae were not observed in larger follicles. 'Loopy' basal laminae were composed of basal laminae aligning the basal surface of basal granulosa cells, but with additional layers or loops often branching from the innermost layer. Each loop was usually < 1 microm long and had vesicles (20-30 nm) attached to the inner aspect. Basal cellular processes were also common, and vesicles could be seen budding off from these processes. In antral follicles, conventional basal laminae occurred in follicles with rounded basal granulosa cells. Other follicles with columnar cells, and atretic follicles, had the 'loopy' basal lamina phenotype. Thus, follicles have different basal laminae that relate to the morphology of the membrana granulosa. PMID:10864785

  3. Mephedrone alters basal ganglia and limbic neurotensin systems

    PubMed Central

    German, Christopher L.; Hoonakker, Amanda H.; Fleckenstein, Annette E.; Hanson, Glen R.

    2014-01-01

    Mephedrone (4-methylmethcathinone) is a synthetic cathinone designer drug that alters presynaptic dopamine (DA) activity like many psychostimulants. However, little is known about the postsynaptic dopaminergic impacts of mephedrone. The neuropeptide neurotensin (NT) provides inhibitory feedback for basal ganglia and limbic DA pathways, and postsynaptic D1-like and D2-like receptor activity affects NT tissue levels. This study evaluated how mephedrone alters basal ganglia and limbic system NT content and the role of NT receptor activation in drug consumption behavior. Four 25 mg/kg injections of mephedrone increased NT content in basal ganglia (striatum, substantia nigra and globus pallidus) and the limbic regions (nucleus accumbens core), while a lower dosage (5 mg/kg/injection) only increased striatal NT content. Mephedrone-induced increases in basal ganglia NT levels were mediated by D1-like receptors in the striatum and the substantia nigra by both D1-like and D2-like receptors in the globus pallidus. Mephedrone increased substance P content, another neuropeptide, in the globus pallidus, but not in the dorsal striatum or substantia nigra. Finally, the NT receptor agonist PD149163 blocked mephedrone self-administration, suggesting reduced NT release, as indicated by increased tissue levels, likely contributing to patterns of mephedrone consumption. PMID:24678634

  4. Basal Cell Carcinoma Developing from Trichoepithelioma: Review of Three Cases

    PubMed Central

    Satyanarayana, M. Ananta; Aryasomayajula, Sirish; Krishna, B.A. Rama

    2016-01-01

    Trichoepitheliomas (TE) are benign tumours but occasionally can undergo transformation to malignant neoplasms more commonly as Basal Cell Carcinoma (BCC). The correct diagnosis between these tumours is very important because basal cell carcinoma is locally aggressive neoplasm and requires total surgical excision with wide healthy margins while trichoepithelioma needs simple excision. We describe three patients who developed basal cell carcinoma with facial trichoepitheliomas. The only clinical feature that distinguished the carcinomas from the trichoepitheliomas was their larger size, in all three patients, one patient with recurrent, hyper pigmented swelling with surface ulceration and in another patient there are multiple trichoepitheliomas, and other family members are also affected. The history, clinical features and histopathological findings were suggestive of the evolution of basal cell carcinoma directly from trichoepithelioma in our first two cases, but in the third case TE and BCC were separate lesions on face and we are uncertain about whether the BCC developed independently or by transformation from a trichoepithelioma. Based on our clinicopathological observations in the three patients and reports in the recent literature, BCC with follicular differentiation and trichoepithelioma are considered to be highly related. PMID:27134936

  5. Writing with Basals: A Sentence Combining Approach to Comprehension.

    ERIC Educational Resources Information Center

    Reutzel, D. Ray; Merrill, Jimmie D.

    Sentence combining techniques can be used with basal readers to help students develop writing skills. The first technique is addition, characterized by using the connecting word "and" to join two or more base sentences together. The second technique is called "embedding," and is characterized by putting parts of two or more base sentences together…

  6. Task-phase-specific dynamics of basal forebrain neuronal ensembles

    PubMed Central

    Tingley, David; Alexander, Andrew S.; Kolbu, Sean; de Sa, Virginia R.; Chiba, Andrea A.; Nitz, Douglas A.

    2014-01-01

    Cortically projecting basal forebrain neurons play a critical role in learning and attention, and their degeneration accompanies age-related impairments in cognition. Despite the impressive anatomical and cell-type complexity of this system, currently available data suggest that basal forebrain neurons lack complexity in their response fields, with activity primarily reflecting only macro-level brain states such as sleep and wake, onset of relevant stimuli and/or reward obtainment. The current study examined the spiking activity of basal forebrain neuron populations across multiple phases of a selective attention task, addressing, in particular, the issue of complexity in ensemble firing patterns across time. Clustering techniques applied to the full population revealed a large number of distinct categories of task-phase-specific activity patterns. Unique population firing-rate vectors defined each task phase and most categories of task-phase-specific firing had counterparts with opposing firing patterns. An analogous set of task-phase-specific firing patterns was also observed in a population of posterior parietal cortex neurons. Thus, consistent with the known anatomical complexity, basal forebrain population dynamics are capable of differentially modulating their cortical targets according to the unique sets of environmental stimuli, motor requirements, and cognitive processes associated with different task phases. PMID:25309352

  7. Basal cell carcinomas in a young woman with Steinert's disease.

    PubMed

    Miraglia, E; Cantisani, C; Giustini, S; Ambrifi, M; Soda, G; Calvieri, S

    2014-08-01

    Steinert's disease or Myotonic dystrophy type I (DM1) is an autosomal dominant disease characterized by myotonia, muscular dystrophy, cataracts, hypogonadism, frontal balding, and electrocardiographic alterations.Several tumors have been associated with DM1 such as pilomatricoma, thymomas and insulinomas. Herein, we describe the unusual onset of multiple basal cell carcinomas in a young woman with DM1. PMID:25148278

  8. Basal ganglia morphology links the metabolic syndrome and depressive symptoms

    PubMed Central

    Onyewuenyi, Ikechukwu C.; Muldoon, Matthew F.; Christie, Israel C.; Erickson, Kirk I.; Gianaros, Peter J.

    2014-01-01

    The metabolic syndrome (MetS) is a clustering of cardiovascular and cerebrovascular risk factors that are often comorbid with depressive symptoms. Individual components of the MetS also covary with the morphology of basal ganglia regions that are altered by depression. However, it remains unknown whether the covariation between the MetS and depressive symptomatology can be accounted for in part by morphological changes in the basal ganglia. Accordingly, we tested the hypothesis that increased depressive symptoms among individuals with the MetS might be statistically mediated by reduced grey matter volume in basal ganglia regions. The presence of the MetS was determined in 147 middle-aged adults using the criteria of the National Cholesterol Education Program, Adult Treatment Panel III. Basal ganglia volumes were determined on an a priori basis by automated segmentation of high-resolution magnetic resonance images. Depressive symptoms were assessed using the Patient Health Questionnaire. Even after controlling for demographic and other confounding factors, having the MetS and meeting more MetS criteria covaried with reduced globus pallidus volume. Meeting more MetS criteria and reduced pallidal volume were also related to depressive symptoms. Moreover, the MetS-depression association was statistically mediated by pallidal volume. In summary, reduced globus pallidus volume is a neural correlate of the MetS that may partly account for its association with depressive symptoms. PMID:24096008

  9. Decodable Texts for Beginning Reading Instruction: The Year 2000 Basals.

    ERIC Educational Resources Information Center

    Hoffman, James V.; Sailors, Misty; Patterson, Elizabeth U.

    2002-01-01

    Describes the features of the first grade texts included in basal readers used for beginning reading instruction in Texas in 2000. Investigates the general features of student texts with respect to the instructional design of the text, the accessibility of the text for beginning readers, and the engaging qualities of the text. Suggests that policy…

  10. [Parkinson's disease and cortico-Basal Ganglia circuits].

    PubMed

    Pan, Ming-Kai; Tai, Chun-Hwei; Kuo, Chung-Chin

    2010-09-01

    Cortico-basal ganglia circuit model has been studied extensively after it was first proposed by Alexander and Crutcher in 1990. This model accurately predicted the hyperactivity of indirect pathway and subthalamic nucleus(STN) in the dopamine deficiency state of Parkinson's disease (PD), prompting the experimental approaches of lesioning STN in parkinsonian primates. Application of these successful experiences with STN lesions in the reversal of parkinsonian symptoms to human PD patients facilitates the development of STN deep brain stimulation (DBS), which has become one of the most important therapies for PD in recent years. Although the classical model of the cortico-basal ganglia circuits by Alexander and Crutcher has provided many important insights into the basal ganglia function, the functional role of cortico-subthalamic "hyperdirect" pathway in the circuits has been relatively neglected. The first part of this article summarizes recent development concerning the cortico-basal ganglia circuits, especially emphasizing the importance of the hyperdirect pathway. In the second part of this article, we would describe the analyses of gross corticobasal ganglia circuit electrophysiological findings, especially emphasizing the coherence between two oscillating signals. We would also discuss the correlation between these parameters and the motor dysfunction, and its pathophysiological implications in PD. PMID:20824544

  11. Sexism in Basal Readers: An Analysis of Male Main Characters.

    ERIC Educational Resources Information Center

    Vaughn-Roberson, Courtney; And Others

    1989-01-01

    Investigated whether positive female traits were attributed to male main characters in six basal readers. Although positive female traits appeared in the male characters, the overall composite and depiction of individual characters indicate that male personalities are dominated by male-linked virtues such as independence and a willingness to take…

  12. Genetics Home Reference: biotin-thiamine-responsive basal ganglia disease

    MedlinePlus

    ... 4 links) Encyclopedia: Basal Ganglia Dysfunction Health Topic: B Vitamins Health Topic: Brain Diseases Health Topic: Movement Disorders ... doi: 10.1055/s-0028-1128152. Epub 2009 Mar 17. Review. Citation on PubMed GeneReview: Biotin-Thiamine-Responsive ...

  13. Marine ice sheet profiles and stability under Coulomb basal conditions

    NASA Astrophysics Data System (ADS)

    Tsai, Victor; Stewart, Andrew; Thompson, Andrew

    2015-04-01

    The behavior of marine-terminating ice sheets, like the West Antarctic Ice Sheet, is of interest due to the possibility of rapid grounding line retreat and consequent catastrophic loss of ice. Critical to modeling this behavior is a choice of basal rheology, where the most popular approach is to relate the ice sheet velocity to a power-law function of basal stress. Recent experiments, however, suggest that near-grounding line tills exhibit Coulomb friction behavior. Here we address how Coulomb conditions modify ice sheet profiles and stability criteria. The basal rheology necessarily transitions to Coulomb friction near the grounding line due to low effective stresses, leading to changes in ice sheet properties within a narrow boundary layer. Ice sheet profiles 'taper off' towards a flatter upper surface, compared to the power-law case, and basal stresses vanish at the grounding line, consistent with observations. In the Coulomb case, the grounding line ice flux also depends more strongly on flotation ice thickness, which implies that ice sheets are more sensitive to climate perturbations. Furthermore, with Coulomb friction, the ice sheet grounds stably in shallower water than with a power-law rheology. This implies that smaller perturbations are required to push the grounding line into regions of negative bed slope, where it would become unstable. These results have important implications for ice sheet stability in a warming climate.

  14. Polarized Integrin Mediates Human Keratinocyte Adhesion to Basal Lamina

    NASA Astrophysics Data System (ADS)

    de Luca, Michele; Tamura, Richard N.; Kajiji, Shama; Bondanza, Sergio; Rossino, Paola; Cancedda, Ranieri; Carlo Marchisio, Pier; Quaranta, Vito

    1990-09-01

    Epithelial cell interactions with matrices are critical to tissue organization. Indirect immunofluorescence and immunoprecipitations of cell lysates prepared from stratified cultures of human epidermal cells showed that the major integrins expressed by keratinocytes are α_Eβ_4 (also called α_6β_4) and α_2β_1/α_3β_1. The α_Eβ_4 integrin is localized at the surface of basal cells in contact with the basement membrane, whereas α_2β_1/ α_3β_1 integrins are absent from the basal surface and are localized only on the lateral surface of basal and spinous keratinocytes. Anti-β_4 antibodies potently inhibited keratinocyte adhesion to matrigel or purified laminin, whereas anti-β_1 antibodies were ineffective. Only anti-β_4 antibodies were able to detach established keratinocyte colonies. These data suggest that α_Eβ_4 mediates keratinocyte adhesion to basal lamina, whereas the β_1 subfamily is involved in cell-cell adhesion of keratinocytes.

  15. Basal ganglion stroke presenting as subtle behavioural change.

    PubMed

    Wagner, Stephanie J; Begaz, T

    2009-01-01

    Cerebral infarctions can have many presentations ranging from hemiparesis to subtle behavioural changes. A case is presented in which the only sign of a left basal ganglion infarct was isolated abulia. This case highlights the importance of a thorough evaluation in cases of acute unexplained changes in behaviour. PMID:21686449

  16. Basal ganglion stroke presenting as subtle behavioural change.

    PubMed

    Wagner, S J; Begaz, T

    2008-07-01

    Cerebral infarctions can have many presentations ranging from hemiparesis to subtle behavioural changes. A case is presented in which the only sign of a left basal ganglion infarct was isolated abulia. This case highlights the importance of a thorough evaluation in cases of acute unexplained changes in behaviour. PMID:18573972

  17. Bilateral basal ganglia activation associated with sensorimotor adaptation.

    PubMed

    Seidler, R D; Noll, D C; Chintalapati, P

    2006-11-01

    Sensorimotor adaptation tasks can be classified into two types. When subjects adapt movements to visual feedback perturbations such as in prism lens adaptation, they perform kinematic adaptations. When subjects adapt movements to force field perturbations such as with robotic manipulanda, they perform kinetic adaptations. Neuroimaging studies have shown basal ganglia involvement in kinetic adaptations, but have found little evidence of basal ganglia involvement in kinematic adaptations, despite reports of deficits in patients with diseases of the basal ganglia, such as Parkinson's and Huntington's disease, in these. In an effort to resolve such apparent discrepancy, we used FMRI to focus on the first few minutes of practice during kinematic adaptation. Human subjects adapted to visuomotor rotations in the context of a joystick aiming task while lying supine in a 3.0 T MRI scanner. As demonstrated previously, early adaptive processes were associated with BOLD activation in the cerebellum and the sensory and motor cortical regions. A novel finding of this study was bilateral basal ganglia activation. This suggests that, at least for early learning, the neural correlates of kinematic adaptation parallel those of other types of skill learning. We observed activation in the right globus pallidus and putamen, along with the right prefrontal, premotor and parietal cortex, which may support spatial cognitive processes of adaptation. We also observed activation in the left globus pallidus and caudate nucleus, along with the left premotor and supplementary motor cortex, which may support the sensorimotor processes of adaptation. These results are the first to demonstrate a clear involvement of basal ganglia activation in this type of kinematic motor adaptation. PMID:16794848

  18. Calving fluxes and basal melt rates of Antarctic ice shelves.

    PubMed

    Depoorter, M A; Bamber, J L; Griggs, J A; Lenaerts, J T M; Ligtenberg, S R M; van den Broeke, M R; Moholdt, G

    2013-10-01

    Iceberg calving has been assumed to be the dominant cause of mass loss for the Antarctic ice sheet, with previous estimates of the calving flux exceeding 2,000 gigatonnes per year. More recently, the importance of melting by the ocean has been demonstrated close to the grounding line and near the calving front. So far, however, no study has reliably quantified the calving flux and the basal mass balance (the balance between accretion and ablation at the ice-shelf base) for the whole of Antarctica. The distribution of fresh water in the Southern Ocean and its partitioning between the liquid and solid phases is therefore poorly constrained. Here we estimate the mass balance components for all ice shelves in Antarctica, using satellite measurements of calving flux and grounding-line flux, modelled ice-shelf snow accumulation rates and a regional scaling that accounts for unsurveyed areas. We obtain a total calving flux of 1,321 ± 144 gigatonnes per year and a total basal mass balance of -1,454 ± 174 gigatonnes per year. This means that about half of the ice-sheet surface mass gain is lost through oceanic erosion before reaching the ice front, and the calving flux is about 34 per cent less than previous estimates derived from iceberg tracking. In addition, the fraction of mass loss due to basal processes varies from about 10 to 90 per cent between ice shelves. We find a significant positive correlation between basal mass loss and surface elevation change for ice shelves experiencing surface lowering and enhanced discharge. We suggest that basal mass loss is a valuable metric for predicting future ice-shelf vulnerability to oceanic forcing. PMID:24037377

  19. Basal jawed vertebrate phylogenomics using transcriptomic data from Solexa sequencing.

    PubMed

    Chen, Ming; Zou, Ming; Yang, Lei; He, Shunping

    2012-01-01

    The traditionally accepted relationships among basal jawed vertebrates have been challenged by some molecular phylogenetic analyses based on mitochondrial sequences. Those studies split extant gnathostomes into two monophyletic groups: tetrapods and piscine branch, including Chondrichthyes, Actinopterygii and sarcopterygian fishes. Lungfish and bichir are found in a basal position on the piscine branch. Based on transcriptomes of an armored bichir (Polypterus delhezi) and an African lungfish (Protopterus sp.) we generated, expressed sequences and whole genome sequences available from public databases, we obtained 111 genes to reconstruct the phylogenetic tree of basal jawed vertebrates and estimated their times of divergence. Our phylogenomic study supports the traditional relationship. We found that gnathostomes are divided into Chondrichthyes and the Osteichthyes, both with 100% support values (posterior probabilities and bootstrap values). Chimaeras were found to have a basal position among cartilaginous fishes with a 100% support value. Osteichthyes were divided into Actinopterygii and Sarcopterygii with 100% support value. Lungfish and tetrapods form a monophyletic group with 100% posterior probability. Bichir and two teleost species form a monophyletic group with 100% support value. The previous tree, based on mitochondrial data, was significantly rejected by an approximately unbiased test (AU test, p = 0). The time of divergence between lungfish and tetrapods was estimated to be 391.8 Ma and the divergence of bichir from pufferfish and medaka was estimated to be 330.6 Ma. These estimates closely match the fossil record. In conclusion, our phylogenomic study successfully resolved the relationship of basal jawed vertebrates based on transtriptomes, EST and whole genome sequences. PMID:22558409

  20. The mechanism of skeletal aragonite neomorphism: evidence from neomorphosed mollusks from the upper Purbeck Formation (Late Jurassic-Early Cretaceous), southern England

    NASA Astrophysics Data System (ADS)

    Maliva, Robert G.; Dickson, J. A. D.

    1992-03-01

    The trace element geochemistry and microtextures of neomorphosed mollusks from the upper Purbeck Formation (Late Jurassic-Early Cretaceous) of southern England suggest that calcite replacement of aragonite occurs by a force of crystallization-driven mechanism similar to that of non-polymorphic skeletal carbonate replacement reactions, such as silicification. The Purbeck neomorphic calcites are substantially enriched in Mg, Mn, and Fe, and depleted in Sr compared to skeletal aragonite indicating that the neomorphic reaction zones were not chemically isolated from the bulk pore waters to a significant degree. Neomorphic calcite microtextures are fundamentally similar to the replacement microtextures of silicified and celestite-replaced fossils, in terms of the degree and style of preservation of traces of skeletal microtextures in authigenic crystals and the relationships of authigenic crystal morphology and crystallographic orientation to shell microtexture. The neomorphic replacement of aragonite by calcite differs from most non-polymorphic replacement reactions in that the calcite cannibalizes aragonite. Decreases in the intraskeletal pore water calcium carbonate ion activity product caused by calcite precipitation results in aragonite dissolution adjacent to aragonite-calcite contacts (i.e., chalkification) in some fossils. Chalkification does not occur in non-polymorphic replacements of skeletal carbonate.

  1. Acetylcholine binding protein of mollusks is unlikely to act as a regulator of cholinergic neurotransmission at neurite-neurite synaptic sites in vivo.

    PubMed

    Banks, Gareth; Kemenes, Ildiko; Schofield, Michael; O'Shea, Michael; Korneev, Sergei A

    2009-09-01

    A population of glial cells in the central nervous system of the gastropod mollusk Lymnaea stagnalis produces a soluble protein that specifically binds acetylcholine. This protein is named the acetylcholine binding protein (AChBP). Experiments performed in vitro indicated that AChBP inactivates released acetylcholine at cholinergic synapses. On the basis of these observations, a similar in vivo role for AChBP was hypothesized. To fulfill this function, AChBP-expressing glia ought to be located in close proximity to cholinergic synapses in vivo. To examine this, we have analyzed the cellular and subcellular expression of AChBP in the intact CNS. Using a variety of molecular techniques, we demonstrate here that AChBP expression is confined to a subpopulation of glial cells located within the peripheral zone of each of the ganglia constituting the CNS. This zone contains the cell bodies of neurons, but few synapses. Conversely, glial cells that do not express the AChBP are predominantly located in the synapse-rich central neuropile zone but are rare in the cell body zone. Thus, our findings are not compatible with the previous conclusions drawn from in vitro studies and suggest that AChBP functions in vivo as a regulator of nonsynaptic cholinergic transmission. PMID:19395478

  2. Fidelity of rocky intertidal mollusks in subtidal death assemblages to their counterpart life assemblages: a case study in San Salvador Island, Bahamas.

    NASA Astrophysics Data System (ADS)

    García-Ramos, Diego A.

    2016-04-01

    Rocky shores preserved in the geological record were rarely reported until a couple of decades ago. Even today, most of the literature focuses on bioerosional features in these high-energy environments due to their higher fossilization potential relative to shell material. Hard parts of taxa adapted to intertidal rocky shores may be preserved as allochthonous material in death assemblages (DAs) formed in adjacent shallow subtidal habitats due to lateral mixing. To test if life assemblages (LAs) of rocky intertidal mollusks (RIM) are faithfully recorded in shallow subtidal DAs, two ~30 m long transects across a proximal-distal gradient were studied on San Salvador Island, Bahamas. These transects encompass a proximal ripple field which grades into a facies dominated by green algae, and a distal ripple field. A total of 22 bulk samples, representing 155 liters of sediment, were wet-sieved with a 2-mm mesh. The samples yielded 528 RIM shells representing 15 species. Unexpectedly, abundance and compositional similarity of RIM shells to counterpart LAs sharply peaks along a belt of lag deposits of coarse sands fringing proximal ripple fields, in transition to green algae communities. These results suggest that, although a substantial transport of intertidal shells takes place in shallow subtidal environments, the signal is diluted in background sediment composition even in close proximity to the shore (30 m), and significant concentrations (loosely packed) of RIM shells in subtidal DAs might be used as a proxy to pinpoint past rocky intertidal environments.

  3. Effects of the Basal Boundary on Debris-flow Dynamics

    NASA Astrophysics Data System (ADS)

    Iverson, R. M.; Logan, M.; Lahusen, R. G.; Berti, M.

    2006-12-01

    Data aggregated from 37 large-scale experiments reveal some counterintuitive effects of bed roughness on debris-flow dynamics. In each experiment 10 m3 of water-saturated sand and gravel, mixed with 1 to 12% silt and clay by dry weight, was abruptly released from a gate at the head of a 2-m wide, 1.2-m deep, 82.5-m long rectangular flume inclined 31° throughout most of its length and adjoined to a gently sloping, planar runout surface at its toe. The flume's basal boundary consisted of either a smooth, planar concrete surface or a concrete surface roughened with a grid of conical bumps. Tilt-table tests with dry debris-flow sediment showed that this roughness imparted a basal friction angle of 38°, comparable to the sediment's internal friction angle of 38-42°, whereas the smooth-bed friction angle was 28°. About 20 electronic sensors installed in the flume yielded data on flow speeds and depths as well as basal stresses and pore pressures. Behavior observed in all experiments included development of steep, unsaturated, coarse-grained debris-flow snouts and tapering, liquefied, fine-grained tails. Flows on the rough bed were typically about 50% thicker and 20% slower than flows on the smooth bed, although the rough bed caused snout steepening that enabled flow fronts to move faster than expected, given the increased bed friction. Moreover, flows on rough beds ran out further than flows on smooth beds owing to enhanced grain-size segregation and lateral levee formation. With the rough bed, measured basal stresses and pore pressures differed little from values expected from static gravitational loading of partially liquefied debris. With the smooth bed, however, measured basal stresses and pore pressures were nearly twice as large as expected values. This anomaly resulted from flow disturbance at the upstream lips of steel plates in which sensors were mounted. The lips produced barely visible ripples in otherwise smooth flow surfaces, yet sufficed to generate

  4. Idiopathic Basal Ganglia Calcification Presented with Impulse Control Disorder

    PubMed Central

    Sahin, Cem; Levent, Mustafa; Akbaba, Gulhan; Kara, Bilge; Yeniceri, Emine Nese; Inanc, Betul Battaloglu

    2015-01-01

    Primary familial brain calcification (PFBC), also referred to as Idiopathic Basal Ganglia Calcification (IBGC) or “Fahr's disease,” is a clinical condition characterized by symmetric and bilateral calcification of globus pallidus and also basal ganglions, cerebellar nuclei, and other deep cortical structures. It could be accompanied by parathyroid disorder and other metabolic disturbances. The clinical features are dysfunction of the calcified anatomic localization. IBGC most commonly presents with mental damage, convulsion, parkinson-like clinical picture, and neuropsychiatric behavior disorders; however, presentation with impulse control disorder is not a frequent presentation. In the current report, a 43-year-old male patient who has been admitted to psychiatry policlinic with the complaints of aggressive behavior episodes and who has been diagnosed with impulse control disorder and IBGC was evaluated in the light of the literature. PMID:26246920

  5. Basal resistance for three of the largest Greenland outlet glaciers

    NASA Astrophysics Data System (ADS)

    Shapero, Daniel R.; Joughin, Ian R.; Poinar, Kristin; Morlighem, Mathieu; Gillet-Chaulet, Fabien

    2016-01-01

    Resistance at the ice-bed interface provides a strong control on the response of ice streams and outlet glaciers to external forcing, yet it is not observable by remote sensing. We used inverse methods constrained by satellite observations to infer the basal resistance to flow underneath three of the Greenland Ice Sheet's largest outlet glaciers. In regions of fast ice flow and high (>250 kPa) driving stresses, ice is often assumed to flow over a strong bed. We found, however, that the beds of these three glaciers provide almost no resistance under the fast-flowing trunk. Instead, resistance to flow is provided by the lateral margins and stronger beds underlying slower-moving ice upstream. Additionally, we found isolated patches of high basal resistivity within the predominantly weak beds. Because these small-scale (<1 ice thickness) features may be artifacts of overfitting our solution to measurement errors, we tested their robustness to different degrees of regularization.

  6. Morphological elucidation of basal ganglia circuits contributing reward prediction

    PubMed Central

    Fujiyama, Fumino; Takahashi, Susumu; Karube, Fuyuki

    2015-01-01

    Electrophysiological studies in monkeys have shown that dopaminergic neurons respond to the reward prediction error. In addition, striatal neurons alter their responsiveness to cortical or thalamic inputs in response to the dopamine signal, via the mechanism of dopamine-regulated synaptic plasticity. These findings have led to the hypothesis that the striatum exhibits synaptic plasticity under the influence of the reward prediction error and conduct reinforcement learning throughout the basal ganglia circuits. The reinforcement learning model is useful; however, the mechanism by which such a process emerges in the basal ganglia needs to be anatomically explained. The actor–critic model has been previously proposed and extended by the existence of role sharing within the striatum, focusing on the striosome/matrix compartments. However, this hypothesis has been difficult to confirm morphologically, partly because of the complex structure of the striosome/matrix compartments. Here, we review recent morphological studies that elucidate the input/output organization of the striatal compartments. PMID:25698913

  7. Morphological elucidation of basal ganglia circuits contributing reward prediction.

    PubMed

    Fujiyama, Fumino; Takahashi, Susumu; Karube, Fuyuki

    2015-01-01

    Electrophysiological studies in monkeys have shown that dopaminergic neurons respond to the reward prediction error. In addition, striatal neurons alter their responsiveness to cortical or thalamic inputs in response to the dopamine signal, via the mechanism of dopamine-regulated synaptic plasticity. These findings have led to the hypothesis that the striatum exhibits synaptic plasticity under the influence of the reward prediction error and conduct reinforcement learning throughout the basal ganglia circuits. The reinforcement learning model is useful; however, the mechanism by which such a process emerges in the basal ganglia needs to be anatomically explained. The actor-critic model has been previously proposed and extended by the existence of role sharing within the striatum, focusing on the striosome/matrix compartments. However, this hypothesis has been difficult to confirm morphologically, partly because of the complex structure of the striosome/matrix compartments. Here, we review recent morphological studies that elucidate the input/output organization of the striatal compartments. PMID:25698913

  8. [Morphological Re-evaluation of the Basal Ganglia Network].

    PubMed

    Fujiyama, Fumino

    2016-07-01

    Electrophysiological studies in monkeys have shown that dopaminergic neurons respond to the reward prediction error. In addition, striatal neurons alter their responsiveness to cortical or thalamic inputs in response to dopamine signals, via dopamine-regulated synaptic plasticity. These findings have led to the hypothesis that the striatum exhibits synaptic plasticity under the influence of reward prediction error and conducts reinforcement learning throughout the basal ganglia circuits. The reinforcement learning model is useful; however, the mechanism by which such a process emerges in the basal ganglia needs to be anatomically explained. The actor-critic model has been previously proposed and extended by the existence of role sharing within the striatum, with particular focus on the striosome and matrix compartments. However, this hypothesis has been difficult to confirm morphologically, partly because of the complex structure of the striosome and matrix compartments. Here, we review recent morphological studies that elucidate the input/output organization of the striatal compartments. PMID:27395470

  9. Is Broca's area part of a basal ganglia thalamocortical circuit?

    PubMed

    Ullman, Michael T

    2006-05-01

    The cortex constituting Broca's area does not exist in isolation. Rather, like other cortical regions, Broca's area is connected to other brain structures, which likely play closely related functional roles. This paper focuses on the basal ganglia, a set of subcortical structures that project through topographically organized "channels" via the thalamus to different frontal regions. It is hypothesized that the basal ganglia project to Broca's area. This circuitry is further posited to encompass at least two channels. One channel can be characterized as subserving procedural memory, while the other underlies the retrieval of knowledge from declarative memory. These hypotheses are supported by both anatomical and functional evidence. Implications and issues for further investigation are discussed. PMID:16881254

  10. Solute effect on basal and prismatic slip systems of Mg.

    PubMed

    Moitra, Amitava; Kim, Seong-Gon; Horstemeyer, M F

    2014-11-01

    In an effort to design novel magnesium (Mg) alloys with high ductility, we present a first principles data based on the Density Functional Theory (DFT). The DFT was employed to calculate the generalized stacking fault energy curves, which can be used in the generalized Peierls-Nabarro (PN) model to study the energetics of basal slip and prismatic slip in Mg with and without solutes to calculate continuum scale dislocation core widths, stacking fault widths and Peierls stresses. The generalized stacking fault energy curves for pure Mg agreed well with other DFT calculations. Solute effects on these curves were calculated for nine alloying elements, namely Al, Ca, Ce, Gd, Li, Si, Sn, Zn and Zr, which allowed the strength and ductility to be qualitatively estimated based on the basal dislocation properties. Based on our multiscale methodology, a suggestion has been made to improve Mg formability. PMID:25273695

  11. Apical versus Basal Neurogenesis Directs Cortical Interneuron Subclass Fate.

    PubMed

    Petros, Timothy J; Bultje, Ronald S; Ross, M Elizabeth; Fishell, Gord; Anderson, Stewart A

    2015-11-10

    Fate determination in the mammalian telencephalon, with its diversity of neuronal subtypes and relevance to neuropsychiatric disease, remains a critical area of study in neuroscience. Most studies investigating this topic focus on the diversity of neural progenitors within spatial and temporal domains along the lateral ventricles. Often overlooked is whether the location of neurogenesis within a fate-restricted domain is associated with, or instructive for, distinct neuronal fates. Here, we use in vivo fate mapping and the manipulation of neurogenic location to demonstrate that apical versus basal neurogenesis influences the fate determination of major subgroups of cortical interneurons derived from the subcortical telencephalon. Somatostatin-expressing interneurons arise mainly from apical divisions along the ventricular surface, whereas parvalbumin-expressing interneurons originate predominantly from basal divisions in the subventricular zone. As manipulations that shift neurogenic location alter interneuron subclass fate, these results add an additional dimension to the spatial-temporal determinants of neuronal fate determination. PMID:26526999

  12. Deformation Studies of NEEM, Greenland Basal Folded Ice

    NASA Astrophysics Data System (ADS)

    Keegan, K.; Dahl-Jensen, D.; Montagnat, M.; Weikusat, I.

    2015-12-01

    Deep Greenland ice cores and airborne radio echo sounding (RES) images have recently revealed that basal ice flow of the Greenland Ice Sheet is very unstable. In many locations, a basal layer of disturbed ice is observed. At the NEEM, Greenland site this folding occurs at the boundary between the Eemian and glacial ice regimes, indicating that differences in physical properties of the ice play a role in the disturbance. Past work in metallurgy and ice suggests that impurity content controls grain evolution and therefore deformation. We hypothesize that the differences in ice flow seen deep in the NEEM ice core are controlled by differences in the impurity content of the ice layers. Here we present results of fabric, grain size, impurity content, and deformation studies from samples above and below this unstable boundary in the ice sheet.

  13. Basal forebrain neuronal inhibition enables rapid behavioral stopping

    PubMed Central

    Mayse, Jeffrey D.; Nelson, Geoffrey M.; Avila, Irene; Gallagher, Michela; Lin, Shih-Chieh

    2015-01-01

    Cognitive inhibitory control, the ability to rapidly suppress responses inappropriate for the context, is essential for flexible and adaptive behavior. While most studies on inhibitory control have focused on the fronto-basal-ganglia circuit, here we explore a novel hypothesis and show that rapid behavioral stopping is enabled by neuronal inhibition in the basal forebrain (BF). In rats performing the stop signal task, putative noncholinergic BF neurons with phasic bursting responses to the go signal were inhibited nearly completely by the stop signal. The onset of BF neuronal inhibition was tightly coupled with and temporally preceded the latency to stop, the stop signal reaction time. Artificial inhibition of BF activity in the absence of the stop signal was sufficient to reproduce rapid behavioral stopping. These results reveal a novel subcortical mechanism of rapid inhibitory control by the BF, which provides bidirectional control over the speed of response generation and inhibition. PMID:26368943

  14. Basal cell adenoma of maxillary sinus mimicking ameloblastoma.

    PubMed

    Bhagde, Priya Anil; Barpande, Suresh Ramchandra; Bhavthankar, Jyoti Dilip; Humbe, Jayanti G

    2016-01-01

    Basal cell adenoma (BCA) is a rare basaloid tumor, with only 20% of cases occurring in minor salivary glands. Histologically, BCA is characterized by the presence of basaloid cells and may frequently be mistaken with canalicular adenoma, basal cell adenocarcinoma, adenoid cystic carcinoma and basaloid squamous cell carcinoma. Immunohistochemistry may aid in arriving at a final diagnosis as in the present case. Reported here is a case of locally aggressive BCA. Histologically, the lesion mimicked ameloblastoma and other entities which posed a diagnostic challenge. There are no reports of BCA presenting as an aggressive lesion available in English literature so far; moreover, merely a single case of BCA of maxillary sinus has been previously reported to the best of our cognition. This case report highlights the rarity of this tumor with regards to its site of origin, clinical behavior and histopathological mimics. PMID:27194878

  15. Basal cell adenoma of maxillary sinus mimicking ameloblastoma

    PubMed Central

    Bhagde, Priya Anil; Barpande, Suresh Ramchandra; Bhavthankar, Jyoti Dilip; Humbe, Jayanti G

    2016-01-01

    Basal cell adenoma (BCA) is a rare basaloid tumor, with only 20% of cases occurring in minor salivary glands. Histologically, BCA is characterized by the presence of basaloid cells and may frequently be mistaken with canalicular adenoma, basal cell adenocarcinoma, adenoid cystic carcinoma and basaloid squamous cell carcinoma. Immunohistochemistry may aid in arriving at a final diagnosis as in the present case. Reported here is a case of locally aggressive BCA. Histologically, the lesion mimicked ameloblastoma and other entities which posed a diagnostic challenge. There are no reports of BCA presenting as an aggressive lesion available in English literature so far; moreover, merely a single case of BCA of maxillary sinus has been previously reported to the best of our cognition. This case report highlights the rarity of this tumor with regards to its site of origin, clinical behavior and histopathological mimics. PMID:27194878

  16. Investigational agents in metastatic basal cell carcinoma: focus on vismodegib

    PubMed Central

    Batty, Nicolas; Kossoff, Ellen; Dy, Grace K

    2012-01-01

    Vismodegib (GDC-0449, 2-chloro-N-(4-chloro-3-(pyridin-2-yl)phenyl)-4-(methylsulfonyl)benzamide, Erivedge™) is a novel first-in-human, first-in class, orally bio-available Hedgehog pathway signaling inhibitor of the G-protein coupled receptor-like protein smoothened (SMO) which was approved in the United States on January 2012. This signaling pathway is involved in the carcinogenesis of several types of tumor, as exemplified by basal cell carcinoma. This review focuses on the role of the Hedgehog pathway in the pathogenesis of basal cell carcinoma, the pharmacology and the clinical activity of vismodegib, as well as a brief summary of investigational agents in development targeting this pathway.

  17. Basal ganglia function, stuttering, sequencing, and repair in adult songbirds

    PubMed Central

    Kubikova, Lubica; Bosikova, Eva; Cvikova, Martina; Lukacova, Kristina; Scharff, Constance; Jarvis, Erich D.

    2014-01-01

    A pallial-basal-ganglia-thalamic-pallial loop in songbirds is involved in vocal motor learning. Damage to its basal ganglia part, Area X, in adult zebra finches has been noted to have no strong effects on song and its function is unclear. Here we report that neurotoxic damage to adult Area X induced changes in singing tempo and global syllable sequencing in all animals, and considerably increased syllable repetition in birds whose song motifs ended with minor repetitions before lesioning. This stuttering-like behavior started at one month, and improved over six months. Unexpectedly, the lesioned region showed considerable recovery, including immigration of newly generated or repaired neurons that became active during singing. The timing of the recovery and stuttering suggest that immature recovering activity of the circuit might be associated with stuttering. These findings indicate that even after juvenile learning is complete, the adult striatum plays a role in higher level organization of learned vocalizations. PMID:25307086

  18. Pure hemidystonia with basal ganglion abnormalities on positron emission tomography

    SciTech Connect

    Perlmutter, J.S.; Raichle, M.E.

    1984-03-01

    We present a patient with hemidystonia and an abnormality of the contralateral basal ganglion seen only with positron emission tomography. A 50-year-old sinistral man suffered minor trauma to the right side of his head and neck. Within 20 minutes he developed paroxysmal intermittent dystonic posturing of his right face, forearm, hand, and foot, with weaker contractions of the left foot, lasting several seconds and recurring every few minutes. Neurological findings between spells were normal. The following were also normal: electrolyte, calcium, magnesium, and arterial blood gas levels, and findings of drug screen, cerebrospinal fluid examination, electroencephalography with nasopharyngeal leads, computed tomographic scanning (initially and four weeks later), and cerebral angiography. Positron emission tomographic scanning revealed abnormalities in the left basal ganglion region, including decreased oxygen metabolism, decreased oxygen extraction, increased blood volume, and increased blood flow.

  19. Multiple keratocystic odontogenic tumors in nevoid basal cell carcinoma syndrome

    PubMed Central

    Pereira, Treville; Tamgadge, Avinash; Sapdhare, Swati; Pujar, Ashwini

    2015-01-01

    Keratocystic odontogenic tumor (KCOT) is of particular interest because its recurrence rate is high and its behavior is aggressive. Nevoid basal cell carcinoma syndrome (NBCCS), which is also known as Gorlin syndrome, is a hereditary condition characterized by a wide range of developmental abnormalities and with a predisposition to neoplasms. These multiple KCOTs have warranted an aggressive treatment at the earliest because of the damage and possible complications. Recurrence of these lesions is a characteristic feature that has to be considered while explaining the prognosis to the patient. Here, we report a case of a 14-year-old boy with clinical features of basal cell nevus syndrome and multiple KCOTs. In addition to the other common features, congenitally missing third molars in all the four quadrants is a feature which has not been previously reported in association with NBCCS in Indian patients. PMID:26981489

  20. Neural representation of time in cortico-basal ganglia circuits

    PubMed Central

    Jin, Dezhe Z.; Fujii, Naotaka; Graybiel, Ann M.

    2009-01-01

    Encoding time is universally required for learning and structuring motor and cognitive actions, but how the brain keeps track of time is still not understood. We searched for time representations in cortico-basal ganglia circuits by recording from thousands of neurons in the prefrontal cortex and striatum of macaque monkeys performing a routine visuomotor task. We found that a subset of neurons exhibited time-stamp encoding strikingly similar to that required by models of reinforcement-based learning: They responded with spike activity peaks that were distributed at different time delays after single task events. Moreover, the temporal evolution of the population activity allowed robust decoding of task time by perceptron models. We suggest that time information can emerge as a byproduct of event coding in cortico-basal ganglia circuits and can serve as a critical infrastructure for behavioral learning and performance. PMID:19850874

  1. MRI of germinomas arising from the basal ganglia and thalamus.

    PubMed

    Kim, D I; Yoon, P H; Ryu, Y H; Jeon, P; Hwang, G J

    1998-08-01

    We reviewed the MRI findings of germinomas originating from the basal ganglia, thalamus or deep white matter in 13 patients with 14 germinomas, excluding those in the suprasellar or pineal regions. Ten cases were confirmed as germinomas by stereotaxic biopsy, three by partial and one by total removal of the tumour. Analysis was focussed on the location and the signal characteristic of the tumour, haemorrhage, cysts within the tumour and any other associated findings. Thirteen of the tumours were in the basal ganglia and one in the thalamus. Haemorrhage was observed in seven patients, while twelve showed multiple cysts. Associated ipsilateral cerebral hemiatrophy was seen in three patients. The signal intensity of the parenchymal germinomas was heterogeneous on T1- and T2-weighted images due to haemorrhage, cysts and solid portions. We also report the MRI findings of germinomas in an early stage in two patients. PMID:9763338

  2. Cerebellar networks with the cerebral cortex and basal ganglia.

    PubMed

    Bostan, Andreea C; Dum, Richard P; Strick, Peter L

    2013-05-01

    The dominant view of cerebellar function has been that it is exclusively concerned with motor control and coordination. Recent findings from neuroanatomical, behavioral, and imaging studies have profoundly changed this view. Neuroanatomical studies using virus transneuronal tracers have demonstrated that cerebellar output reaches vast areas of the neocortex, including regions of prefrontal and posterior parietal cortex. Furthermore, it has recently become clear that the cerebellum is reciprocally connected with the basal ganglia, which suggests that the two subcortical structures are part of a densely interconnected network. Taken together, these findings elucidate the neuroanatomical substrate for cerebellar involvement in non-motor functions mediated by the prefrontal and posterior parietal cortex, as well as in processes traditionally associated with the basal ganglia. PMID:23579055

  3. Following basal stem rot in young oil palm plantings.

    PubMed

    Panchal, G; Bridge, P D

    2005-01-01

    The PCR primer GanET has previously been shown to be suitable for the specific amplification of DNA from Ganoderma boninense. A DNA extraction and PCR method has been developed that allows for the amplification of the G. boninense DNA from environmental samples of oil palm tissue. The GanET primer reaction was used in conjunction with a palm-sampling programme to investigate the possible infection of young palms through cut frond base surfaces. Ganoderma DNA was detected in frond base material at a greater frequency than would be expected by comparison with current infection levels. Comparisons are made between the height of the frond base infected, the number of frond bases infected, and subsequent development of basal stem rot. The preliminary results suggest that the development of basal stem rot may be more likely to occur when young lower frond bases are infected. PMID:15750744

  4. Observing ice-shelf channels and basal melting from space

    NASA Astrophysics Data System (ADS)

    Berger, Sophie; Drews, Reinhard; Helm, Veit; Rack, Wolfgang; Lenaerts, Jan; Ligtenberg, Stefan; Pattyn, Frank

    2016-04-01

    Ice-shelf channels (along-flow lineations in which ice is thinner) are ubiquitous in Antarctic ice shelves. Although these features are readily visible in satellite imagery, ice-thickness and ice-velocity variations in their surrounding are typically heavily undersampled. Ice-shelf channels focus channelized melting and significantly alter the basal mass balance (and hence ice-shelf stability) on short horizontal scales. Here we use interferometrically-derived TandDEM-X digital elevation models and ice-flow velocities with a horizontal gridding of 125 m illustrating the ice-shelf dynamics of the Roi Baudouin Ice Shelf, Dronning Maud Land (East Antarctica) in unprecedented detail. Using ground-based GPS surface elevation, we demonstrate that TanDEM-X is an ideal sensor to map the channel morphology at the ice-shelf surface. We find velocity anomalies surrounding the channels along the entire ice shelf potentially indicating the presence of locally elevated basal melt rates. Using mass conservation in a Lagrangian framework, we find basal melt rates averaging 0.4 m/a in the middle of the ice shelf and peaking at 12 m/a inside some channels. We illustrate the sensitivity of the method with respect to systematic biases in elevation/velocity and also with respect to lateral variations of the depth-density relationship. With the increased availability of high-resolution radar satellites (such as Sentinel1), the techniques presented here could be applied on an pan-Antarctic scale to map basal melting both in space and time at high-resolution.

  5. Autofluorescence imaging of basal cell carcinoma by smartphone RGB camera

    NASA Astrophysics Data System (ADS)

    Lihachev, Alexey; Derjabo, Alexander; Ferulova, Inesa; Lange, Marta; Lihacova, Ilze; Spigulis, Janis

    2015-12-01

    The feasibility of smartphones for in vivo skin autofluorescence imaging has been investigated. Filtered autofluorescence images from the same tissue area were periodically captured by a smartphone RGB camera with subsequent detection of fluorescence intensity decreasing at each image pixel for further imaging the planar distribution of those values. The proposed methodology was tested clinically with 13 basal cell carcinoma and 1 atypical nevus. Several clinical cases and potential future applications of the smartphone-based technique are discussed.

  6. Pure psychic akinesia with bilateral lesions of basal ganglia.

    PubMed Central

    Laplane, D; Baulac, M; Widlöcher, D; Dubois, B

    1984-01-01

    Three patients showed dramatic psychic akinesia after recovery from toxic encephalopathy. They had no or only mild motor disorders. The spontaneous psychic akinesia was reversible when the patient was stimulated, as if there was a loss of self psychic activation. Intellectual capacities were normal. Two patients had stereotyped behaviours resembling compulsions. In all patients CT cans showed bilateral lesions in the basal ganglia, mainly within the globus pallidus. Images PMID:6726263

  7. Movement Disorders Following Cerebrovascular Lesion in the Basal Ganglia Circuit.

    PubMed

    Park, Jinse

    2016-05-01

    Movement disorders are primarily associated with the basal ganglia and the thalamus; therefore, movement disorders are more frequently manifest after stroke compared with neurological injuries associated with other structures of the brain. Overall clinical features, such as types of movement disorder, the time of onset and prognosis, are similar with movement disorders after stroke in other structures. Dystonia and chorea are commonly occurring post-stroke movement disorders in basal ganglia circuit, and these disorders rarely present with tremor. Rarer movement disorders, including tic, restless leg syndrome, and blepharospasm, can also develop following a stroke. Although the precise mechanisms underlying the pathogenesis of these conditions have not been fully characterized, disruptions in the crosstalk between the inhibitory and excitatory circuits resulting from vascular insult are proposed to be the underlying cause. The GABA (gamma-aminobutyric acid)ergic and dopaminergic systems play key roles in post-stroke movement disorders. This review summarizes movement disorders induced by basal ganglia and thalamic stroke according to the anatomical regions in which they manifest. PMID:27240808

  8. Autoimmunity and the basal ganglia: new insights into old diseases.

    PubMed

    Dale, R C

    2003-03-01

    Sydenham's chorea (SC) occurs weeks or months after Group A streptococcal infection, and is characterized by involuntary, purposeless movements of the limbs, in addition to behavioural alteration. There is a body of evidence which suggests that SC is an immune-mediated brain disorder with regional localization to the basal ganglia. Recent reports have suggested that the spectrum of post-streptococcal CNS disease is broader than chorea alone, and includes other hyperkinetic movement disorders (tics, dystonia and myoclonus). In addition, there are high rates of behavioural sequelae, particularly emotional disorders such as obsessive-compulsive disorder, anxiety and depression. These findings have lead to the hypothesis that similar immune-mediated basal ganglia processes may be operating in common neuropsychiatric disease such as tic disorders, Tourette syndrome and obsessive-compulsive disorder. This review analyses the historical aspects of post-streptococcal CNS disease, and the recent immunological studies which have addressed the hypothesis that common neuropsychiatric disorders may be secondary to basal ganglia autoimmunity. PMID:12615982

  9. Saccade learning with concurrent cortical and subcortical basal ganglia loops

    PubMed Central

    N'Guyen, Steve; Thurat, Charles; Girard, Benoît

    2014-01-01

    The Basal Ganglia (BG) is a central structure involved in multiple cortical and subcortical loops. Some of these loops are believed to be responsible for saccade target selection. We study here how the very specific structural relationships of these saccadic loops can affect the ability of learning spatial and feature-based tasks. We propose a model of saccade generation with reinforcement learning capabilities based on our previous BG and superior colliculus models. It is structured around the interactions of two parallel cortico-basal loops and one tecto-basal loop. The two cortical loops separately deal with spatial and non-spatial information to select targets in a concurrent way. The subcortical loop is used to make the final target selection leading to the production of the saccade. These different loops may work in concert or disturb each other regarding reward maximization. Interactions between these loops and their learning capabilities are tested on different saccade tasks. The results show the ability of this model to correctly learn basic target selection based on different criteria (spatial or not). Moreover the model reproduces and explains training dependent express saccades toward targets based on a spatial criterion. Finally, the model predicts that in absence of prefrontal control, the spatial loop should dominate. PMID:24795615

  10. Neuroimaging in basal ganglia disorders: perspectives for transcranial ultrasound.

    PubMed

    Becker, G; Berg, D

    2001-01-01

    Transcranial sonography is a new diagnostic tool, allowing not only the evaluation of cerebral arteries but also the two-dimensional display of the brain parenchyma. In this review we will summarize basics of the application, the ultrasound anatomy of the brain and sonographic findings in some movement disorders. While in normal adults basal ganglia nuclei are hypoechogenic, they are hyperechogenic in certain basal ganglia disorders. In Parkinson's disease, for example, the substantia nigra can be depicted as a distinctly echogenic area. An elevated echogenicity of the lentiform nuclei was noticed in patients with primary adult-onset dystonia. In both disorders the altered echogenicity may arise from higher heavy metal tissue content (i.e. iron in Parkinson's disease and copper in primary dystonia). Our findings converge to the hypothesis that transcranial ultrasound sensitively detects pathological metal accumulation not identified by other neuroimaging techniques (CT and MRI) and therefore provides new insights in the diagnosis of basal ganglia disorders. The implications of these findings for the understanding of the pathogenesis and its usefulness for the early diagnosis of movement disorders are outlined. PMID:11215589

  11. Basal fat oxidation decreases with aging in women.

    PubMed

    Calles-Escandón, J; Arciero, P J; Gardner, A W; Bauman, C; Poehlman, E T

    1995-01-01

    The present study tested the hypothesis that a decrease in basal fat oxidation in aging women is related to a loss of fat-free mass. Thirty-two nonsmoking women with a wide range of age (18-73 yr) were characterized for body composition (underwater weight), maximal aerobic capacity, and basal fat oxidation (indirect calorimetry). Results showed that fat oxidation was negatively correlated with age (r2 = 0.17, P = 0.017) but was positively correlated with the fat-free mass (r2 = 0.48, P < 0.0001) and with the level of aerobic fitness (maximal aerobic capacity) (r2 = 0.22, P = 0.007). Unexpectedly, fat oxidation had no relationship with fat mass (r2 = 0.07, P = 0.136). Partial correlation analysis showed that the decline in fat-free mass, and not the age or maximal O2 consumption, was the best single predictor of the decline in basal fat oxidation. These results support the theory that a decrease in fat oxidation with advancing age in healthy women is associated with a decrease in the fat-free mass and not age per se. Interventions that increase or preserve the quantity of fat-free mass (e.g., exercise training) may enhance fat oxidation and thus lessen the age-associated adiposity in women. PMID:7713822

  12. Movement Disorders Following Cerebrovascular Lesion in the Basal Ganglia Circuit

    PubMed Central

    Park, Jinse

    2016-01-01

    Movement disorders are primarily associated with the basal ganglia and the thalamus; therefore, movement disorders are more frequently manifest after stroke compared with neurological injuries associated with other structures of the brain. Overall clinical features, such as types of movement disorder, the time of onset and prognosis, are similar with movement disorders after stroke in other structures. Dystonia and chorea are commonly occurring post-stroke movement disorders in basal ganglia circuit, and these disorders rarely present with tremor. Rarer movement disorders, including tic, restless leg syndrome, and blepharospasm, can also develop following a stroke. Although the precise mechanisms underlying the pathogenesis of these conditions have not been fully characterized, disruptions in the crosstalk between the inhibitory and excitatory circuits resulting from vascular insult are proposed to be the underlying cause. The GABA (gamma-aminobutyric acid)ergic and dopaminergic systems play key roles in post-stroke movement disorders. This review summarizes movement disorders induced by basal ganglia and thalamic stroke according to the anatomical regions in which they manifest. PMID:27240808

  13. Basal ganglia correlates of fatigue in young adults

    PubMed Central

    Nakagawa, Seishu; Takeuchi, Hikaru; Taki, Yasuyuki; Nouchi, Rui; Kotozaki, Yuka; Shinada, Takamitsu; Maruyama, Tsukasa; Sekiguchi, Atsushi; Iizuka, Kunio; Yokoyama, Ryoichi; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Miyauchi, Carlos Makoto; Magistro, Daniele; Sakaki, Kohei; Jeong, Hyeonjeong; Sasaki, Yukako; Kawashima, Ryuta

    2016-01-01

    Although the prevalence of chronic fatigue is approximately 20% in healthy individuals, there are no studies of brain structure that elucidate the neural correlates of fatigue outside of clinical subjects. We hypothesized that fatigue without evidence of disease might be related to changes in the basal ganglia and prefrontal cortex and be implicated in fatigue with disease. We aimed to identify the white matter structures of fatigue in young subjects without disease using magnetic resonance imaging (MRI). Healthy young adults (n = 883; 489 males and 394 females) were recruited. As expected, the degrees of fatigue and motivation were associated with larger mean diffusivity (MD) in the right putamen, pallidus and caudate. Furthermore, the degree of physical activity was associated with a larger MD only in the right putamen. Accordingly, motivation was the best candidate for widespread basal ganglia, whereas physical activity might be the best candidate for the putamen. A plausible mechanism of fatigue may involve abnormal function of the motor system, as well as areas of the dopaminergic system in the basal ganglia that are associated with motivation and reward. PMID:26893077

  14. Field measurement of basal forces generated by erosive debris flows

    USGS Publications Warehouse

    McCoy, S.W.; Tucker, G.E.; Kean, J.W.; Coe, J.A.

    2013-01-01

    It has been proposed that debris flows cut bedrock valleys in steeplands worldwide, but field measurements needed to constrain mechanistic models of this process remain sparse due to the difficulty of instrumenting natural flows. Here we present and analyze measurements made using an automated sensor network, erosion bolts, and a 15.24 cm by 15.24 cm force plate installed in the bedrock channel floor of a steep catchment. These measurements allow us to quantify the distribution of basal forces from natural debris‒flow events that incised bedrock. Over the 4 year monitoring period, 11 debris‒flow events scoured the bedrock channel floor. No clear water flows were observed. Measurements of erosion bolts at the beginning and end of the study indicated that the bedrock channel floor was lowered by 36 to 64 mm. The basal force during these erosive debris‒flow events had a large‒magnitude (up to 21 kN, which was approximately 50 times larger than the concurrent time‒averaged mean force), high‒frequency (greater than 1 Hz) fluctuating component. We interpret these fluctuations as flow particles impacting the bed. The resulting variability in force magnitude increased linearly with the time‒averaged mean basal force. Probability density functions of basal normal forces were consistent with a generalized Pareto distribution, rather than the exponential distribution that is commonly found in experimental and simulated monodispersed granular flows and which has a lower probability of large forces. When the bed sediment thickness covering the force plate was greater than ~ 20 times the median bed sediment grain size, no significant fluctuations about the time‒averaged mean force were measured, indicating that a thin layer of sediment (~ 5 cm in the monitored cases) can effectively shield the subjacent bed from erosive impacts. Coarse‒grained granular surges and water‒rich, intersurge flow had very similar basal force distributions despite

  15. Butyltins, polyaromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls in sediments and bivalve mollusks in a mid-latitude environment from the Patagonian coastal zone.

    PubMed

    Commendatore, Marta G; Franco, Marcos A; Gomes Costa, Patricia; Castro, Italo B; Fillmann, Gilberto; Bigatti, Gregorio; Esteves, José L; Nievas, Marina L

    2015-12-01

    Butyltins (BTs), polyaromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) were assessed in a mid-latitude environment of the Patagonian coast, distant from significant pollutant sources. Bioaccumulation processes through bottom sediment resuspension were suggested by BTs level (expressed as ng of tin [Sn] g(-1) dry wt) found in surface sediment (mollusks (29.4-206.0 ng [Sn] g(-1) dry wt); whereas imposex incidence was only 15% in the gastropod Pareuthria plumbea collected near a harbor. Low hydrocarbon pollution was found in sediments and bivalves with ∑PAHs(16) ranging from

  16. Identification and transcriptional analysis of two types of lectins (SgCTL-1 and SgGal-1) from mollusk Solen grandis.

    PubMed

    Wei, Xiumei; Yang, Jianmin; Liu, Xiangquan; Yang, Dinglong; Xu, Jie; Fang, Jinghui; Wang, Weijun; Yang, Jialong

    2012-08-01

    C-type lectin and galectin are two types of animal carbohydrate-binding proteins which serve as pathogen recognition molecules and play crucial roles in the innate immunity of invertebrates. In the present study, a C-type lectin (designated as SgCTL-1) and galectin (designated as SgGal-1) were identified from mollusk Solen grandis, and their expression patterns, both in tissues and toward three pathogen-associated molecular patterns (PAMPs) stimulation were characterized. The full-length cDNA of SgCTL-1 and SgGal-1 was 1280 and 1466 bp, containing an open reading frame (ORF) of 519 and 1218 bp, respectively. Their deduced amino acid sequences showed high similarity to other members of C-type lectin and galectin superfamily, respectively. SgCTL-1 encoded a single carbohydrate-recognition domain (CRD), and the motif of Ca(2+)-binding site 2 was EPN (Glu(135)-Pro(136)-Asn(137)). While SgGal-1 encoded two CRDs, and the amino acid residues constituted the carbohydrate-binding motifs were well conserved in CRD1 but partially conserved in CRD2. Although SgCTL-1 and SgGal-1 exhibited different tissue expression pattern, they were both constitutively expressed in all tested tissues, including hemocytes, gonad, mantle, muscle, gill and hepatopancreas, and they were both highly expressed in hepatopancreas and gill. Furthermore, the mRNA expression of two lectins in hemocytes was significantly (P < 0.01) up-regulated with different levels after S. grandis were stimulated by lipopolysaccharide (LPS), peptidoglycan (PGN) or β-1,3-glucan. Our results suggested that SgCTL-1 and SgGal-1 from razor clam were two novel members of animal lectins, and they might function as pattern recognition receptors (PRRs) taking part in the process of pathogen recognition. PMID:22565020

  17. Direct injection of tissue extracts in liquid chromatography/tandem mass spectrometry for the determination of pharmaceuticals and other contaminants of emerging concern in mollusks.

    PubMed

    Bayen, Stéphane; Estrada, Elvagris Segovia; Juhel, Guillaume; Kelly, Barry C

    2015-07-01

    In the present study, a straightforward approach was validated for the analysis of pharmaceutically active compounds and endocrine-disrupting chemicals in the mollusk tissues, with a focus on two species commonly consumed in Southeast Asia (green mussels: Perna viridis; lokan clams: Polymesoda expansa). This approach relied on a simple solvent extraction (shaker table) followed by direct injection in liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). This "cleanup-free" approach was made possible by the use of isotopically labeled surrogates (to correct for matrix effects) and a post-column switch on the LC-MS/MS system (to remove potential interfering material). Altogether, relative recoveries were satisfactory for 36 out of 44 compounds (26-163% range) and excellent for 27 out of 44 compounds (79-107% range). Method detection limits (MDLs) were usually expressed in the nanogram per gram wet weight (ww) range and below. The method was successfully applied to 16 batches of green mussel samples collected in Singapore coastal waters. Trace levels of six compounds were detected in mussel tissues: caffeine (0.22-1.55 ng g(-1) ww), carbamazepine (

  18. A 'conovenomic' analysis of the milked venom from the mollusk-hunting cone snail Conus textile--the pharmacological importance of post-translational modifications.

    PubMed

    Bergeron, Zachary L; Chun, Joycelyn B; Baker, Margaret R; Sandall, David W; Peigneur, Steve; Yu, Peter Y C; Thapa, Parashar; Milisen, Jeffrey W; Tytgat, Jan; Livett, Bruce G; Bingham, Jon-Paul

    2013-11-01

    Cone snail venoms provide a largely untapped source of novel peptide drug leads. To enhance the discovery phase, a detailed comparative proteomic analysis was undertaken on milked venom from the mollusk-hunting cone snail, Conus textile, from three different geographic locations (Hawai'i, American Samoa and Australia's Great Barrier Reef). A novel milked venom conopeptide rich in post-translational modifications was discovered, characterized and named α-conotoxin TxIC. We assign this conopeptide to the 4/7 α-conotoxin family based on the peptide's sequence homology and cDNA pre-propeptide alignment. Pharmacologically, α-conotoxin TxIC demonstrates minimal activity on human acetylcholine receptor models (100 μM, <5% inhibition), compared to its high paralytic potency in invertebrates, PD50 = 34.2 nMol kg(-1). The non-post-translationally modified form, [Pro](2,8)[Glu](16)α-conotoxin TxIC, demonstrates differential selectivity for the α3β2 isoform of the nicotinic acetylcholine receptor with maximal inhibition of 96% and an observed IC50 of 5.4 ± 0.5 μM. Interestingly its comparative PD50 (3.6 μMol kg(-1)) in invertebrates was ~100 fold more than that of the native peptide. Differentiating α-conotoxin TxIC from other α-conotoxins is the high degree of post-translational modification (44% of residues). This includes the incorporation of γ-carboxyglutamic acid, two moieties of 4-trans hydroxyproline, two disulfide bond linkages, and C-terminal amidation. These findings expand upon the known chemical diversity of α-conotoxins and illustrate a potential driver of toxin phyla-selectivity within Conus. PMID:24055806

  19. What's New in Research and Treatment of Basal and Squamous Cell Skin Cancers?

    MedlinePlus

    ... for basal and squamous cell skin cancers What’s new in basal and squamous cell skin cancer research? ... cancer cells. Researchers are working to apply this new information to strategies for preventing and treating skin ...

  20. Basal body structure and cell cycle-dependent biogenesis in Trypanosoma brucei.

    PubMed

    Vaughan, Sue; Gull, Keith

    2015-01-01

    Basal bodies are microtubule-based organelles that assemble cilia and flagella, which are critical for motility and sensory functions in all major eukaryotic lineages. The core structure of the basal body is highly conserved, but there is variability in biogenesis and additional functions that are organism and cell type specific. Work carried out in the protozoan parasite Trypanosoma brucei has arguably produced one of the most detailed dissections of basal body structure and biogenesis within the context of the flagellar pocket and associated organelles. In this review, we provide a detailed overview of the basic basal body structure in T. brucei along with the accessory structures and show how basal body movements during the basal body duplication cycle orchestrate cell and organelle morphogenesis. With this in-depth three-dimensional knowledge, identification of many basal body genes coupled with excellent genetic tools makes it an attractive model organism to study basal body biogenesis and maintenance. PMID:26862392

  1. Metastatic basal cell carcinoma caused by carcinoma misdiagnosed as acne - case report and literature review.

    PubMed

    Aydin, Dogu; Hölmich, Lisbet Rosenkrantz; Jakobsen, Linda P

    2016-06-01

    Basal cell carcinoma can be misdiagnosed as acne; thus, carcinoma should be considered in treatment-resistant acne. Although rare, neglected basal cell carcinoma increases the risk of metastasis. PMID:27398205

  2. Basal cell carcinoma develops in contact with the epidermal basal cell layer - a three-dimensional morphological study.

    PubMed

    Pirici, Ionica; Ciurea, Marius Eugen; Mîndrilă, Ion; Avrămoiu, Ioan; Pirici, Alexandru; Nicola, Monica Georgiana; Rogoveanu, Otilia Constantina

    2016-01-01

    Basal cell carcinoma is the most common malignant tumor of the skin, and it develops most frequently on the areas of the body that make its treatment and care extremely difficult, especially in cases of neglecting or aggressive growth and invasion. Both typical mild cases as well as locally aggressive tumor types do not tend to metastasize, and it has been postulated that they should share some common biological and morphological features that might explain this behavior. In this study, we have utilized a high-resolution three-dimensional reconstruction technique on pathological samples from 15 cases of common aggressive (fibrosing and adenoid types) and mild (superficial type) basal cell carcinomas, and showed that all these types shared contact points and bridges with the underlying basal cell layer of the epidermis or with the outmost layer of the hair follicle. The connections found had in fact the highest number for fibrosing type (100%), compared to the superficial (85.71%) and adenoid (55%) types. The morphology of the connection bridges was also different, adjacent moderate to abundant inflammatory infiltrate seeming to lead to a loss of basaloid features in these areas. For the adenoid type, tumor islands seemed to be connected also to each other more strongly, forming a common "tumor lace", and while it has been showed that superficial and fibrosing types have higher recurrence risks, all together these data might iterate a connection between the number of bridging points and the biological and clinical manifestation of this skin tumor. PMID:27151694

  3. Basal Cell Carcinoma of the Penis: A Case Report and Review of the Literature

    PubMed Central

    Roewe, R. J.; Uhlman, Matthew A.; Bockholt, Nathan A.

    2014-01-01

    Basal cell carcinoma of the penis is an extremely rare entity, accounting for less than 0.03% of all basal cell carcinomas. Fortunately, wide local excision of such lesions is generally curative. Fewer than 25 cases have been reported in the literature describing penile basal cell carcinoma. Here we report a case of penile basal cell carcinoma cured with wide local excision. PMID:25298901

  4. A patient centred approach to basal insulin choice for the management of type 2 diabetes mellitus.

    PubMed

    Kalra, Sanjay; Gupta, Yashdeep

    2016-03-01

    Basal insulins are first line injectable therapy by all international guidelines. Basal insulins can be used alone, in combination with metformin, dual or triple oral therapy, glucagon-like peptide receptor agonists, or prandial insulin. However, all basal insulins are not similar. This article proposes objective parameters, and suggests a simple checklist, using history, physical examination, and investigations, to help choose the appropriate preparation, viz degludec, detemir, glargine or NPH insulin, for persons requiring basal insulin. PMID:26968297

  5. Two Cases of Nevoid Basal Cell CarcinomaSyndrome in One Family

    PubMed Central

    Ryu, Dong Jin; Kwon, Yeon Sook; Roh, Mi Ryung

    2008-01-01

    The nevoid basal cell carcinoma syndrome, or Gorlin-Goltz syndrome, is an autosomal dominant multiple system disorder with high penetrance and variable expressions, although it can also arise spontaneously. The diagnostic criteria for nevoid basal cell carcinoma syndrome include multiple basal cell carcinomas, palmoplantar pits, multiple odontogenic keratocysts, skeletal anomalies, positive family history, ectopic calcification and neurological anomalies. We report a brother and sister who were both diagnosed with nevoid basal cell carcinoma syndrome. PMID:27303197

  6. Basal Ganglia Shapes Predict Social, Communication, and Motor Dysfunctions in Boys with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Qiu, Anqi; Adler, Marcy; Crocetti, Deana; Miller, Michael I.; Mostofsky, Stewart H.

    2010-01-01

    Objective: Basal ganglia abnormalities have been suggested as contributing to motor, social, and communicative impairments in autism spectrum disorder (ASD). Volumetric analyses offer limited ability to detect localized differences in basal ganglia structure. Our objective was to investigate basal ganglia shape abnormalities and their association…

  7. Basal physiological parameters in domesticated tree shrews (Tupaia belangeri chinensis).

    PubMed

    Wang, Jing; Xu, Xin-Li; Ding, Ze-Yang; Mao, Rong-Rong; Zhou, Qi-Xin; Lü, Long-Bao; Wang, Li-Ping; Wang, Shuang; Zhang, Chen; Xu, Lin; Yang, Yue-Xiong

    2013-04-01

    Establishing non-human primate models of human diseases is an efficient way to narrow the large gap between basic studies and translational medicine. Multifold advantages such as simplicity of breeding, low cost of feeding and facility of operating make the tree shrew an ideal non-human primate model proxy. Additional features like vulnerability to stress and spontaneous diabetic characteristics also indicate that the tree shrew could be a potential new animal model of human diseases. However, basal physiological indexes of tree shrew, especially those related to human disease, have not been systematically reported. Accordingly, we established important basal physiological indexes of domesticated tree shrews including several factors: (1) body weight, (2) core body temperature and rhythm, (3) diet metabolism, (4) locomotor rhythm, (5) electroencephalogram, (6) glycometabolism and (7) serum and urinary hormone level and urinary cortisol rhythm. We compared the physiological parameters of domesticated tree shrew with that of rats and macaques. Results showed that (a) the core body temperature of the tree shrew was 39.59±0.05 ℃, which was higher than that of rats and macaques; (b) Compared with wild tree shrews, with two activity peaks, domesticated tree shrews had only one activity peak from 17:30 to 19:30; (c) Compared with rats, tree shrews had poor carbohydrate metabolism ability; and (d) Urinary cortisol rhythm indicated there were two peaks at 8:00 and 17:00 in domesticated tree shrews, which matched activity peaks in wild tree shrews. These results provided basal physiological indexes for domesticated tree shrews and laid an important foundation for diabetes and stress-related disease models established on tree shrews. PMID:23572369

  8. A phylogenomic approach to resolve the basal pterygote divergence.

    PubMed

    Simon, Sabrina; Strauss, Sascha; von Haeseler, Arndt; Hadrys, Heike

    2009-12-01

    One of the most fascinating Bauplan transitions in the animal kingdom was the invention of insect wings, a change that also contributed to the success and enormous diversity of this animal group. However, the origin of insect flight and the relationships of basal winged insect orders are still controversial. Three hypotheses have been proposed to explain the phylogeny of winged insects: 1) the traditional Palaeoptera hypothesis (Ephemeroptera + Odonata, Neoptera), 2) the Metapterygota hypothesis (Ephemeroptera, Odonata + Neoptera), and 3) the Chiastomyaria hypothesis (Odonata, Ephemeroptera + Neoptera). Neither phylogenetic analyses of single genes nor even multiple marker systems (e.g., molecular markers + morphological characters) have yet been able to conclusively resolve basal pterygote divergences. A possible explanation for the lack of resolution is that the divergences took place in the mid-Devonian within a short period of time and attempts to solve this problem have been confounded by the major challenge of finding molecular markers to accurately track these short ancient internodes. Although phylogenomic data are available for Neoptera and some wingless (apterygote) orders, they are lacking for the crucial Odonata and Ephemeroptera orders. We adopt a multigene approach including data from two new expressed sequence tag projects-from the orders Ephemeroptera (Baetis sp.) and Odonata (Ischnura elegans)-to evaluate the potential of phylogenomic analyses in clarifying this unresolved issue. We analyzed two data sets that differed in represented taxa, genes, and overall sequence lengths: maxspe (15 taxa, 125 genes, and 31,643 amino acid positions) and maxgen (8 taxa, 150 genes, and 42,541 amino acid positions). Maximum likelihood and Bayesian inference analyses both place the Odonata at the base of the winged insects. Furthermore, statistical hypotheses testing rejected both the Palaeoptera and the Metapterygota hypotheses. The comprehensive molecular data set

  9. Basal salivary cortisol secretion and susceptibility to upper respiratory infection.

    PubMed

    Janicki-Deverts, Denise; Cohen, Sheldon; Turner, Ronald B; Doyle, William J

    2016-03-01

    The immunosuppressive effects of glucocorticoids (GCs) are well-established. However, whether the net effect of GC-elicited alterations in immune function is sufficient to influence a clinically relevant outcome in healthy adults has yet to be shown. The aim of the present study was to investigate whether inter-individual differences in basal salivary cortisol production are associated with increased risk and severity of infection and subsequent illness following experimental exposure to a virus that causes the common cold. The present analyses combine archival data from three viral-challenge studies. Participants were 608 healthy adults, aged 18 to 55 years (49.2% female; 65.8% white), who each completed a three-day saliva collection protocol; was subsequently exposed to a virus that causes the common cold; and monitored for 5 days for objective signs of infection (presence of challenge virus in nasal secretions) and clinical illness (mucus weight, mucociliary clearance time). Basal cortisol production (operationalized as the calculated area-under-the-curve averaged across the 3 days) showed a graded association with infection risk, with those producing higher levels of cortisol being at greater risk. Cortisol also showed a continuous association with duration of viral shedding, an indicator of viral replication and continuing infection, such that higher cortisol concentrations predicted more days of shedding. Cortisol was not, however, related to severity of objective illness. These findings are the first to demonstrate in healthy adults an association between basal cortisol production and an objectively measured and clinically relevant infectious disease outcome. PMID:26778776

  10. Understanding Parkinsonian handwriting through a computational model of basal ganglia.

    PubMed

    Gangadhar, Garipelli; Joseph, Denny; Chakravarthy, V Srinivasa

    2008-10-01

    Handwriting in Parkinson's disease (PD) is typically characterized by micrographia, jagged line contour, and unusual fluctuations in pen tip velocity. Although PD handwriting features have been used for diagnostics, they are not based on a signaling model of basal ganglia (BG). In this letter, we present a computational model of handwriting generation that highlights the role of BG. When PD conditions like reduced dopamine and altered dynamics of the subthalamic nucleus and globus pallidus externa subsystems are simulated, the handwriting produced by the model manifested characteristic PD handwriting distortions like micrographia and velocity fluctuations. Our approach to PD modeling is in tune with the perspective that PD is a dynamic disease. PMID:18386983

  11. Neglected basal cell carcinoma in a schizophrenic patient.

    PubMed

    Shah, Hassan A; Lee, Hui Bae Harold; Nunery, William R

    2008-01-01

    Obtaining informed consent from patients with mental disorders can be a complicated and involved process, potentially resulting in decisions contrary to the advice of physicians. We present a schizophrenic patient with an invasive basal cell carcinoma involving the periocular structures and the right orbit. Exenteration was recommended with en bloc resection of the tumor. The ethical and legal committees decided against surgical intervention. Rather, the patient was admitted for medical treatment of his mental illness. A multidisciplinary approach with consultation of a psychiatrist, social worker, and ethical and legal committees is often necessary in the care of patients with mental illness. PMID:19033856

  12. Hypotensive hemorrhagic necrosis in basal ganglia and brainstem.

    PubMed

    Opeskin, K; Burke, M P

    2000-12-01

    Hypotensive hemorrhagic necrosis of the basal ganglia and brainstem has only occasionally been described. Three such cases are reported. Cardiac arrest had occurred in all cases, and it took at least 1 hour to restore adequate circulation. The patients remained comatose for 2 days to 2 weeks until death. Persistent hypotension causing ischemia in the distribution of deep perforating arteries is considered to have been the key underlying mechanism. Hemorrhage is thought to have been caused by extravasation of red blood cells through damaged blood vessels. PMID:11111807

  13. A Case of Axillary Adenoid Basal Cell Carcinoma

    PubMed Central

    Kim, Soo Ho; Ko, Woo Tae; Lee, Jong Im

    2008-01-01

    Basal cell carcinoma (BCC) is the most common skin cancer with a steadily increasing incidence. Ultraviolet radiation is considered the single most important risk factor for BCC, because the tumor occurs most frequently in sun-exposed areas of the body, with approximately four of five BCCs occurring on the face. BCC occurs infrequently in non-sun-exposed skin. The axilla is one of the most sun-protected areas of the body, and BCC arising at this site is very rare. We herein report a case of adenoid BCC which arose from the axilla in a 33-year-old woman. PMID:27303153

  14. Dermoscopic features of small size pigmented basal cell carcinomas.

    PubMed

    Takahashi, Asuka; Hara, Hiroyuki; Aikawa, Miwa; Ochiai, Toyoko

    2016-05-01

    Dermoscopic images of histologically proven pigmented basal cell carcinomas (BCC) were retrospectively assessed to compare the dermoscopic features of BCC of 3 mm or less in diameter (n = 6) with BCC of 4-6 mm in diameter (n = 11). All lesions lacked the presence of a pigment network. BCC with a diameter of 3 mm or less had fewer positive dermoscopic features compared with the 4-6 mm in diameter BCC. Multiple blue-gray globules and large blue-gray ovoid nests were frequently present. Dermoscopy is a useful tool for early diagnosis of pigmented BCC, even when they are small. PMID:26458728

  15. Pedunculopontine nucleus and basal ganglia: distant relatives or part of the same family?

    PubMed

    Mena-Segovia, Juan; Bolam, J Paul; Magill, Peter J

    2004-10-01

    The basal ganglia are more highly interconnected with the pedunculopontine tegmental nucleus (PPN) than with any other brain region. Regulation and relay of basal ganglia activity are two key functions of the PPN. The PPN provides an interface for the basal ganglia to influence sleep and waking, and the two structures are similarly implicated in learning, reward and other cognitive functions. Perturbations of basal ganglia activity have consequences for the PPN and vice versa, exemplified by their interdependencies in motor function and Parkinson's disease. Thus, close anatomical and physiological links between the PPN and basal ganglia make it increasingly difficult to consider the two as separate functional entities. PMID:15374668

  16. A ground-water inventory of the Waialua basal-water body, Island of Oahu, Hawaii

    USGS Publications Warehouse

    Dale, Robert H.

    1978-01-01

    The Waialua basal-water body underlies an area of about 18 square miles on the north shore of the island of Oahu, Hawaii. The basal-water body is a body of fresh ground water that floats on saline ground water in a highly permeable and porous basaltic aquifer. Inflow to the basal-water body is from the deep infiltration of applied irrigation water and from leakage through a low permeability ground-water dam. Outflow from the basal-water body is from basal-water pumpage and leakage through low-permeability boundaries that separate the basal-water body from the ocean. The basal-water flux, computed as either the sum of the inflow terms or the sum of the outflow terms, is about the same value. The basal-water flux is 55 million gallons per day, (206,000 cubic meters per day), based on the sum of the outflow terms. The effective porosity was computed at 0.09 by a time-series analysis of the covariations in deep infiltration, pumpage, and basal-water head. The volume of basal water in storage is estimated to be 1.4 x 1011 gallons (5.4 x 108 cubic meters). Pumpage from the basal-water body can be increased. The most efficient development method is the skimming shaft. If shafts were used, an additional 15 million gallons per day could be pumped on a sustained basis.

  17. Basal Complex and Basal Venation of Odonata Wings: Structural Diversity and Potential Role in the Wing Deformation

    PubMed Central

    Rajabi, H.; Ghoroubi, N.; Malaki, M.; Darvizeh, A.; Gorb, S. N.

    2016-01-01

    Dragonflies and damselflies, belonging to the order Odonata, are known to be excellent fliers with versatile flight capabilities. The ability to fly over a wide range of speeds, high manoeuvrability and great agility are a few characteristics of their flight. The architecture of the wings and their structural elements have been found to play a major role in this regard. However, the precise influence of individual wing components on the flight performance of these insects remains unknown. The design of the wing basis (so called basal complex) and the venation of this part are responsible for particular deformability and specific shape of the wing blade. However, the wing bases are rather different in representatives of different odonate groups. This presumably reflects the dimensions of the wings on one hand, and different flight characteristics on the other hand. In this article, we develop the first three-dimensional (3D) finite element (FE) models of the proximal part of the wings of typical representatives of five dragonflies and damselflies families. Using a combination of the basic material properties of insect cuticle, a linear elastic material model and a nonlinear geometric analysis, we simulate the mechanical behaviour of the wing bases. The results reveal that although both the basal venation and the basal complex influence the structural stiffness of the wings, it is only the latter which significantly affects their deformation patterns. The use of numerical simulations enabled us to address the role of various wing components such as the arculus, discoidal cell and triangle on the camber formation in flight. Our study further provides a detailed representation of the stress concentration in the models. The numerical analysis presented in this study is not only of importance for understanding structure-function relationship of insect wings, but also might help to improve the design of the wings for biomimetic micro-air vehicles (MAVs). PMID:27513753

  18. Basal Complex and Basal Venation of Odonata Wings: Structural Diversity and Potential Role in the Wing Deformation.

    PubMed

    Rajabi, H; Ghoroubi, N; Malaki, M; Darvizeh, A; Gorb, S N

    2016-01-01

    Dragonflies and damselflies, belonging to the order Odonata, are known to be excellent fliers with versatile flight capabilities. The ability to fly over a wide range of speeds, high manoeuvrability and great agility are a few characteristics of their flight. The architecture of the wings and their structural elements have been found to play a major role in this regard. However, the precise influence of individual wing components on the flight performance of these insects remains unknown. The design of the wing basis (so called basal complex) and the venation of this part are responsible for particular deformability and specific shape of the wing blade. However, the wing bases are rather different in representatives of different odonate groups. This presumably reflects the dimensions of the wings on one hand, and different flight characteristics on the other hand. In this article, we develop the first three-dimensional (3D) finite element (FE) models of the proximal part of the wings of typical representatives of five dragonflies and damselflies families. Using a combination of the basic material properties of insect cuticle, a linear elastic material model and a nonlinear geometric analysis, we simulate the mechanical behaviour of the wing bases. The results reveal that although both the basal venation and the basal complex influence the structural stiffness of the wings, it is only the latter which significantly affects their deformation patterns. The use of numerical simulations enabled us to address the role of various wing components such as the arculus, discoidal cell and triangle on the camber formation in flight. Our study further provides a detailed representation of the stress concentration in the models. The numerical analysis presented in this study is not only of importance for understanding structure-function relationship of insect wings, but also might help to improve the design of the wings for biomimetic micro-air vehicles (MAVs). PMID:27513753

  19. Mephedrone alters basal ganglia and limbic dynorphin systems

    PubMed Central

    German, Christopher L.; Alburges, Mario E.; Hoonakker, Amanda J.; Fleckenstein, Annette E.; Hanson, Glen R.

    2014-01-01

    Mephedrone (4-methymethcathinone) is a synthetic cathinone designer drug that disrupts central nervous system (CNS) dopamine (DA) signaling. Numerous central neuropeptide systems reciprocally interact with dopaminergic neurons to provide regulatory counterbalance, and are altered by aberrant DA activity associated with stimulant exposure. Endogenous opioid neuropeptides are highly concentrated within dopaminergic CNS regions and facilitate many rewarding and aversive properties associated with drug use. Dynorphin, an opioid neuropeptide and kappa receptor agonist, causes dysphoria and aversion to drug consumption through signaling within the basal ganglia and limbic systems, which is affected by stimulants. This study evaluated how mephedrone alters basal ganglia and limbic system dynorphin content, and the role of DA signaling in these changes. Repeated mephedrone administrations (4 × 25 mg/kg/injection, 2-h intervals) selectively increased dynorphin content throughout the dorsal striatum and globus pallidus, decreased dynorphin content within the frontal cortex, and did not alter dynorphin content within most limbic system structures. Pre-treatment with D1-like (SCH-23380) or D2-like (eticlopride) antagonists blocked mephedrone-induced changes in dynorphin content in most regions examined, indicating altered dynorphin activity is a consequence of excessive DA signaling. PMID:25155699

  20. Basal Plane Affinity of an Insect Antifreeze Protein

    NASA Astrophysics Data System (ADS)

    Pertaya, N.; Gauthier, S. Y.; Davies, P. L.; Braslavsky, I.

    2007-03-01

    sbwAFP is a powerful antifreeze protein (AFP) with high thermal hysteresis activity that protects spruce budworm (sbw) from freezing during harsh winters in the spruce and fir forests of USA and Canada. Different types of antifreeze proteins have been found in many other species and have potential applications in cryomedicine and cryopreservation. When an ice crystal is cooled in the presence of AFP below the non-equilibrium freezing point the crystal will suddenly and rapidly grow in specific directions. Hyperactive antifreezes like sbwAFP expand perpendicular to the c-axis (in the plane of the a-axes), whereas moderately active AFPs, like type III from fish, grow in the direction parallel to the c-axis. It has been proposed that the basis for hyperactivity of certain AFPs is that they bind and accumulate on the basal plane to inhibit c-axial growth. By putting fluorescent tags on these two types of AFPs we have been able to directly visualize the binding of different types of AFPs to ice surfaces. We do indeed find that the insect AFP accumulates on the basal plane of an ice crystal while type III AFP does not. Supported by CIHR and BNTI.

  1. Energy intake and basal metabolic rate during maintenance chemotherapy.

    PubMed

    Bond, S A; Han, A M; Wootton, S A; Kohler, J A

    1992-02-01

    Energy intakes and basal metabolic rates were determined in 26 children receiving chemotherapy in remission from acute lymphoblastic leukaemia or solid tumours and 26 healthy controls matched for age and sex. Body weight and height on the two groups were comparable, although one patient was stunted (height for age) and three others wasted (weight for height). Energy intake in the patients at 7705 kJ/day (1842 kcal) and controls at 7773 kJ/day (1866 kcal)) and basal metabolic rate (BMR) in the patients at 4873 kJ/day (1172 kcal) and controls 4987 kJ/day (1196 kcal) for the two groups were not significantly different. Although the energy intake:BMR ratio for both groups was 1.59, the range of values for the patient group was large (0.96-2.73) and appeared to be greater than that observed in the control group (1.23-2.46). These results demonstrated that during this period of chemotherapy there was no evidence of raised energy expenditure at rest or reduced energy intake in the patient group. No indication of undernutrition in the patients as a group was evident, although some individuals might require further clinical nutritional assessment. PMID:1543386

  2. Familial idiopathic basal ganglia calcification (Fahr’s disease)

    PubMed Central

    Mufaddel, Amir A.; Al-Hassani, Ghanem A.

    2014-01-01

    Familial idiopathic basal ganglia calcification (Fahr’s disease) is a rare neurodegenerative disorder characterized by symmetrical and bilateral calcification of the basal ganglia. Calcifications may also occur in other brain regions such as dentate nucleus, thalamus, and cerebral cortex. Both familial and non-familial cases of Fahr’s disease have been reported, predominantly with autosomal-dominant fashion. The disease has a wide range of clinical presentations, predominantly with neuropsychiatric features and movement disorders. Psychiatric features reported in the literature include: cognitive impairment, depression, hallucinations, delusions, manic symptoms, anxiety, schizophrenia-like psychosis, and personality change. Other clinical features include: Parkinsonism, ataxia, headache, seizures, vertigo, stroke-like events, orthostatic hypotension, tremor, dysarthria, and paresis. Fahr’s disease should be considered in the differential diagnosis of psychiatric symptoms, particularly when associated with movement disorder. The disease should be differentiated from other conditions that can cause intracranial calcification. No specific treatment is currently available. Further research is needed to bridge the gap existing in our current knowledge of the prevalence, etiology, symptoms, and treatment of Fahr’s disease. PMID:24983277

  3. The evolution of floral biology in basal angiosperms.

    PubMed

    Endress, Peter K

    2010-02-12

    In basal angiosperms (including ANITA grade, magnoliids, Choranthaceae, Ceratophyllaceae) almost all bisexual flowers are dichogamous (with male and female functions more or less separated in time), and nearly 100 per cent of those are protogynous (with female function before male function). Movements of floral parts and differential early abscission of stamens in the male phase are variously associated with protogyny. Evolution of synchronous dichogamy based on the day/night rhythm and anthesis lasting 2 days is common. In a few clades in Magnoliales and Laurales heterodichogamy has also evolved. Beetles, flies and thrips are the major pollinators, with various degrees of specialization up to large beetles and special flies in some large-flowered Nymphaeaceae, Magnoliaceae, Annonaceae and Aristolochiaceae. Unusual structural specializations are involved in floral biological adaptations (calyptras, inner staminodes, synandria and food bodies, and secretory structures on tepals, stamens and staminodes). Numerous specializations that are common in monocots and eudicots are absent in basal angiosperms. Several families are poorly known in their floral biology. PMID:20047868

  4. Shell bone histology indicates terrestrial palaeoecology of basal turtles

    PubMed Central

    Scheyer, Torsten M; Sander, P.Martin

    2007-01-01

    The palaeoecology of basal turtles from the Late Triassic was classically viewed as being semi-aquatic, similar to the lifestyle of modern snapping turtles. Lately, this view was questioned based on limb bone proportions, and a terrestrial palaeoecology was suggested for the turtle stem. Here, we present independent shell bone microstructural evidence for a terrestrial habitat of the oldest and basal most well-known turtles, i.e. the Upper Triassic Proterochersis robusta and Proganochelys quenstedti. Comparison of their shell bone histology with that of extant turtles preferring either aquatic habitats or terrestrial habitats clearly reveals congruence with terrestrial turtle taxa. Similarities in the shell bones of these turtles are a diploe structure with well-developed external and internal cortices, weak vascularization of the compact bone layers and a dense nature of the interior cancellous bone with overall short trabeculae. On the other hand, ‘aquatic’ turtles tend to reduce cortical bone layers, while increasing overall vascularization of the bone tissue. In contrast to the study of limb bone proportions, the present study is independent from the uncommon preservation of appendicular skeletal elements in fossil turtles, enabling the palaeoecological study of a much broader range of incompletely known turtle taxa in the fossil record. PMID:17519193

  5. Unilateral germinomas involving the basal ganglia and thalamus.

    PubMed

    Kobayashi, T; Kageyama, N; Kida, Y; Yoshida, J; Shibuya, N; Okamura, K

    1981-07-01

    Clinical characteristics of six cases of germinoma involving a unilateral basal ganglion and thalamus are summarized. The incidence was estimated as 10% of all intracranial germinomas. The average age at the onset was 10.5 years. The sex incidence showed a male dominance. The clinical course was slowly progressive, and the average duration between onset and diagnosis was 2 years 5 months. Common symptoms and signs were hemiparesis in all cases, fever of unknown origin and eye symptoms in most, mental deterioration and psychiatric signs in three, and convulsions, pubertas praecox, and diabetes insipidus in two. Signs of increased intracranial pressure were found in only two cases in the later state of the disease. Early diagnosis is difficult because of nonspecific symptomatology and slow progression. Carotid angiography and pneumoencephalography showed abnormal findings compatible with basal ganglia and thalamic tumors, but not specific to germinoma. Ipsilateral cortical atrophy and ventricular dilatation might be significant findings. Radioisotope scanning was useful. Computerized tomography scans were the best method of detecting the location and nature of this tumor, and repeat scans showed response to radiation therapy. PMID:7241216

  6. Energy intake and basal metabolic rate during maintenance chemotherapy.

    PubMed Central

    Bond, S A; Han, A M; Wootton, S A; Kohler, J A

    1992-01-01

    Energy intakes and basal metabolic rates were determined in 26 children receiving chemotherapy in remission from acute lymphoblastic leukaemia or solid tumours and 26 healthy controls matched for age and sex. Body weight and height on the two groups were comparable, although one patient was stunted (height for age) and three others wasted (weight for height). Energy intake in the patients at 7705 kJ/day (1842 kcal) and controls at 7773 kJ/day (1866 kcal)) and basal metabolic rate (BMR) in the patients at 4873 kJ/day (1172 kcal) and controls 4987 kJ/day (1196 kcal) for the two groups were not significantly different. Although the energy intake:BMR ratio for both groups was 1.59, the range of values for the patient group was large (0.96-2.73) and appeared to be greater than that observed in the control group (1.23-2.46). These results demonstrated that during this period of chemotherapy there was no evidence of raised energy expenditure at rest or reduced energy intake in the patient group. No indication of undernutrition in the patients as a group was evident, although some individuals might require further clinical nutritional assessment. PMID:1543386

  7. TBP domain symmetry in basal and activated archaeal transcription.

    PubMed

    Ouhammouch, Mohamed; Hausner, Winfried; Geiduschek, E Peter

    2009-01-01

    The TATA box binding protein (TBP) is the platform for assembly of archaeal and eukaryotic transcription preinitiation complexes. Ancestral gene duplication and fusion events have produced the saddle-shaped TBP molecule, with its two direct-repeat subdomains and pseudo-two-fold symmetry. Collectively, eukaryotic TBPs have diverged from their present-day archaeal counterparts, which remain highly symmetrical. The similarity of the N- and C-halves of archaeal TBPs is especially pronounced in the Methanococcales and Thermoplasmatales, including complete conservation of their N- and C-terminal stirrups; along with helix H'1, the C-terminal stirrup of TBP forms the main interface with TFB/TFIIB. Here, we show that, in stark contrast to its eukaryotic counterparts, multiple substitutions in the C-terminal stirrup of Methanocaldococcus jannaschii (Mja) TBP do not completely abrogate basal transcription. Using DNA affinity cleavage, we show that, by assembling TFB through its conserved N-terminal stirrup, Mja TBP is in effect ambidextrous with regard to basal transcription. In contrast, substitutions in either its N- or the C-terminal stirrup abrogate activated transcription in response to the Lrp-family transcriptional activator Ptr2. PMID:19007415

  8. Coordinated Beating of Algal Flagella is Mediated by Basal Coupling

    NASA Astrophysics Data System (ADS)

    Wan, Kirsty; Goldstein, Raymond

    Cilia or flagella often exhibit synchronized behavior. This includes phase-locking, as seen in Chlamydomonas, and metachronal wave formation in the respiratory cilia of higher organisms. Since the observations by Gray and Rothschild of phase synchrony of nearby swimming spermatozoa, it has been a working hypothesis that synchrony arises from hydrodynamic interactions between beating filaments. Recent work on the dynamics of physically separated pairs of flagella isolated from the multicellular alga Volvox has shown that hydrodynamic coupling alone is sufficient for synchrony. However, the situation is more complex when considering multiple flagella on a single cell. We suggest that a mechanism, internal to the cell, provides an additional flagellar coupling. For instance, flagella of Chlamydomonas mutants deficient in filamentary connections between basal bodies are found to display markedly different synchronization from the wildtype. Diverse flagellar coordination strategies found in quadri-, octo- and hexadecaflagellates reveal further evidence that intracellular couplings between flagellar basal bodies compete with hydrodynamic interactions to determine the precise form of flagellar synchronization in unicellular algae.

  9. Metric analysis of basal sphenoid angle in adult human skulls

    PubMed Central

    Netto, Dante Simionato; Nascimento, Sergio Ricardo Rios; Ruiz, Cristiane Regina

    2014-01-01

    Objective To analyze the variations in the angle basal sphenoid skulls of adult humans and their relationship to sex, age, ethnicity and cranial index. Methods The angles were measured in 160 skulls belonging to the Museum of the Universidade Federal de São Paulo Department of Morphology. We use two flexible rules and a goniometer, having as reference points for the first rule the posterior end of the ethmoidal crest and dorsum of the sella turcica, and for the second rule the anterior margin of the foramen magnum and clivus, measuring the angle at the intersection of two. Results The average angle was 115.41°, with no statistical correlation between the value of the angle and sex or age. A statistical correlation was noted between the value of the angle and ethnicity, and between the angle and the horizontal cranial index. Conclusions The distribution of the angle basal sphenoid was the same in sex, and there was correlation between the angle and ethnicity, being the proportion of non-white individuals with an angle >125° significantly higher than that of whites with an angle >125°. There was correlation between the angle and the cranial index, because skulls with higher cranial index tend to have higher basiesfenoidal angle too. PMID:25295452

  10. Photodynamic therapy in the treatment of basal cell carcinoma

    PubMed Central

    Matei, C; Tampa, M; Poteca, T; Panea-Paunica, G; Georgescu, SR; Ion, RM; Popescu, SM; Giurcaneanu, C

    2013-01-01

    Photodynamic therapy (PDT) is a medical procedure based on the activation of the molecules of various exogenous or endogenous chemical substances called photosensitizers by a light source emitting radiation of an adequate wavelength, usually situated in the visible spectrum; photosensitizers are chemical compounds bearing the capacity to selectively concentrate in the neoplastic cells. The energy captured by the molecules of these substances pervaded in the tumor cells is subsequently discharged in the surrounding tissue, triggering certain photodynamic reactions that result in the destruction of the tumor. The procedure is applicable in numerous medical fields. Skin basal cell carcinoma (BCC), the most frequent type of cancer of the human species, is a cutaneous tumor that responds very well to this innovative treatment method. By reviewing numerous recent studies in the field, this article aims to present the role and the indications of photodynamic therapy in the management of basal cell carcinoma, as well as the most important results achieved so far by this therapy in the field of dermato-oncology. PMID:23599819

  11. Coordinated beating of algal flagella is mediated by basal coupling.

    PubMed

    Wan, Kirsty Y; Goldstein, Raymond E

    2016-05-17

    Cilia and flagella often exhibit synchronized behavior; this includes phase locking, as seen in Chlamydomonas, and metachronal wave formation in the respiratory cilia of higher organisms. Since the observations by Gray and Rothschild of phase synchrony of nearby swimming spermatozoa, it has been a working hypothesis that synchrony arises from hydrodynamic interactions between beating filaments. Recent work on the dynamics of physically separated pairs of flagella isolated from the multicellular alga Volvox has shown that hydrodynamic coupling alone is sufficient to produce synchrony. However, the situation is more complex in unicellular organisms bearing few flagella. We show that flagella of Chlamydomonas mutants deficient in filamentary connections between basal bodies display markedly different synchronization from the wild type. We perform micromanipulation on configurations of flagella and conclude that a mechanism, internal to the cell, must provide an additional flagellar coupling. In naturally occurring species with 4, 8, or even 16 flagella, we find diverse symmetries of basal body positioning and of the flagellar apparatus that are coincident with specific gaits of flagellar actuation, suggesting that it is a competition between intracellular coupling and hydrodynamic interactions that ultimately determines the precise form of flagellar coordination in unicellular algae. PMID:27140605

  12. Basal ganglia and thalamic morphology in schizophrenia and bipolar disorder

    PubMed Central

    Womer, Fay Y.; Wang, Lei; Alpert, Kathryn; Smith, Matthew J.; Csernansky, John G.; Barch, Deanna; Mamah, Daniel

    2014-01-01

    In this study, we examined the morphology of the basal ganglia and thalamus in bipolar disorder (BP), schizophrenia-spectrum disorders (SCZ-S), and healthy controls (HC) with particular interest in differences related to the absence or presence of psychosis. Volumetric and shape analyses of the basal ganglia and thalamus were performed in 33 BP individuals [12 without history of psychotic features (NPBP) and 21 with history of psychotic features (PBP)], 32 SCZ-S individuals [28 with SCZ and 4 with schizoaffective disorder], and 27 HC using FreeSurfer-initiated large deformation diffeomorphic metric mapping. Significant volume differences were found in the caudate and globus pallidus, with volumes smallest in the NPBP group. Shape abnormalities showing inward deformation of superior regions of the caudate were observed in BP (and especially in NPBP) compared with HC. Shape differences were also found in the globus pallidus and putamen when comparing the BP and SCZ-S groups. No significant differences were seen in the nucleus accumbens and thalamus. In summary, structural abnormalities in the caudate and globus pallidus are present in BP and SCZ-S. Differences were more apparent in the NPBP subgroup. The findings herein highlight the potential importance of separately examining BP subgroups in neuroimaging studies. PMID:24957866

  13. Coordinated beating of algal flagella is mediated by basal coupling

    PubMed Central

    Wan, Kirsty Y.; Goldstein, Raymond E.

    2016-01-01

    Cilia and flagella often exhibit synchronized behavior; this includes phase locking, as seen in Chlamydomonas, and metachronal wave formation in the respiratory cilia of higher organisms. Since the observations by Gray and Rothschild of phase synchrony of nearby swimming spermatozoa, it has been a working hypothesis that synchrony arises from hydrodynamic interactions between beating filaments. Recent work on the dynamics of physically separated pairs of flagella isolated from the multicellular alga Volvox has shown that hydrodynamic coupling alone is sufficient to produce synchrony. However, the situation is more complex in unicellular organisms bearing few flagella. We show that flagella of Chlamydomonas mutants deficient in filamentary connections between basal bodies display markedly different synchronization from the wild type. We perform micromanipulation on configurations of flagella and conclude that a mechanism, internal to the cell, must provide an additional flagellar coupling. In naturally occurring species with 4, 8, or even 16 flagella, we find diverse symmetries of basal body positioning and of the flagellar apparatus that are coincident with specific gaits of flagellar actuation, suggesting that it is a competition between intracellular coupling and hydrodynamic interactions that ultimately determines the precise form of flagellar coordination in unicellular algae. PMID:27140605

  14. Basal shear stress of debris flow in the runout phase

    NASA Astrophysics Data System (ADS)

    D'Agostino, V.; Bettella, F.; Cesca, M.

    2013-11-01

    A laboratory device is proposed to assess the basal shear stresses generated by debris-flow mixtures during their runout phase. The device consists of an inclinable box with a gate facing a deposition plane. The box is filled with a selected debris-flow mixture, and after sudden opening of the gate, the features of the dam-break deposit can be measured. Based on some simplified assumptions of the energy balance, a methodology is proposed to assess basal shear stresses. The device has been tested using sediment samples from debris-flow deposits generated by two catchments of the Dolomites (Cortina d'Ampezzo, Belluno, Italy) by carrying out runout tests for different sediment concentrations by volume. The results show how the static Coulomb friction law is valid in the runout phase, with friction angles on the order of the angle of repose of the same material in dry conditions. The data elaboration also yields an innovative constitutive equation for shear stresses. This relation merges the Coulomb mixture approach with the concept of a one-phase flow with a certain rheology. This integration offers a useful insight into the weaknesses of the rheological approach if it is not properly scaled up to the ambient pressure of interest.

  15. Anomalous N-glycan structures with an internal fucose branched to GlcA and GlcN residues isolated from a Mollusk shell-forming fluid

    PubMed Central

    Zhou, Hui; Hanneman, Andrew J.; Chasteen, N. Dennis

    2013-01-01

    This report describes the structural details of a unique N-linked valence epitope on the major protein within the extrapallial (EP) fluid of the mollusk, Mytilus edulis. Fluids from this area are considered to be responsible for shell expansion by a self-assembly process that provides an organic framework for the growth of CaCO3 crystals. Previous reports from our laboratories have described the purification and amino acid sequence of this EP protein which was found to be a glycoprotein (EPG) of approximately 28 KDa with 14.3% carbohydrate on a single N-linked consensus site. Described herein is the the de novo sequence of the major glycan and its glycomers. The sequence was determined by ion trap mass spectrometer (ITMSn) resolving structure by tracking precursor-product relationships through successive rounds of collision induced disassociation (CID), thereby spatially resolving linkage and branching details within the confines of the ion trap. Three major glycomers were detected, each possessing a 6-linked fucosylated N-linked core. Two glycans possessed four and five identical antennae, while the third possessed four antennas, but with an additional methylfucose 2-linked to the glucuronic acid moiety, forming a pentasaccharide. The tetrasaccharide structure was: 4-O-methyl-GlcA(1-4)[GlcNAc(1-3)]Fuc(1-4)GlcNAc, while the pentasaccharide was shown to be: mono-O-methyl-Fuc(1-2)-4-O-methyl-GlcA(1-4)[GlcNAc(1-3)]Fuc(1-4)GlcNAc. Samples were differentially deuteriomethylated (CD3/CH3) to localize indigenous methylation, further analyzed by HRMS to confirm monomer compositions, and finally GC-MS to assign structural and stereoisomers. The interfacial shell surface location of this major extrapallial glycoprotein, its calcium heavy metal binding properties and unique structure suggests a probable role in shell formation and possibly metal ion detoxification. A closely related terminal tetrasaccharide structure has been reported in spermatozoan glycolipids of freshwater

  16. Spatial Variation of Basal Conditions on Kamb Ice Stream

    NASA Astrophysics Data System (ADS)

    Jacobel, R. W.; Welch, B. C.; Osterhouse, D.; Pettersson, R.; MacGregor, J. A.

    2007-12-01

    Radar profiles of bed echo intensity provide a way to survey conditions at the ice-bed interface and test for the presence or absence of water. However, extracting information about bed properties from bed echo intensities requires an estimate of the dielectric attenuation loss through the ice. A recent survey [MacGregor et al., 2007] found that the few reported values of depth-averaged attenuation rates in West Antarctica vary by a factor of 3, presumably due to spatial variations in the chemistry and temperature profiles of the ice. Thus, a single value for depth-averaged ice-sheet attenuation cannot be assumed, even over a relatively small region. We measured attenuation rates at several locations on and near Kamb Ice Stream (KIS) by examining basal echo intensity values as a function of ice thickness from constant-offset radar data acquired in 2004-2006. Our values obtained for Siple Dome of 29 dB/km agree with previous measurements [Gades et al., 2000] and the recent calculations and model results of MacGregor et al. [2007]. On KIS, we measured attenuation values of 20 dB/km over the "sticky spot", where ice has become stagnant. This value is consistent with an attenuation model over the sticky spot calculated using borehole temperature data [Engelhardt, 2005] and chemistry data from the Siple Dome ice core. Our radar profiles in the main trunk region of KIS yield a slightly lower value of 15 dB/km, presumably because colder ice is still being advected from inland West Antarctica. Using these values of attenuation, we calculated the basal radar reflectivity at the ice-bed interface in the regions of all our surveys. We found that most regions of the bed in the trunk of KIS have high basal reflectivities and that these values are similar to those obtained in locations where water was found in the Caltech boreholes [Engelhardt, 2005]. Areas of lower bed reflectivity are limited to the sticky spot, where a borehole found a dry bed, and along the margins of KIS

  17. Queuing of concurrent movement plans by basal ganglia.

    PubMed

    Bhutani, Neha; Sureshbabu, Ramakrishnan; Farooqui, Ausaf A; Behari, Madhuri; Goyal, Vinay; Murthy, Aditya

    2013-06-12

    How the brain converts parallel representations of movement goals into sequential movements is not known. We tested the role of basal ganglia (BG) in the temporal control of movement sequences by a convergent approach involving inactivation of the BG by muscimol injections into the caudate nucleus of monkeys and assessing behavior of Parkinson's disease patients, performing a modified double-step saccade task. We tested a critical prediction of a class of competitive queuing models that explains serial behavior as the outcome of a selection of concurrently activated goals. In congruence with these models, we found that inactivation or impairment of the BG unmasked the parallel nature of goal representations such that a significantly greater extent of averaged saccades, curved saccades, and saccade sequence errors were observed. These results suggest that the BG perform a form of competitive queuing, holding the second movement plan in abeyance while the first movement is being executed, allowing the proper temporal control of movement sequences. PMID:23761894

  18. A dystonic syndrome associated with anti-basal ganglia antibodies.

    PubMed

    Edwards, M J; Dale, R C; Church, A J; Giovannoni, G; Bhatia, K P

    2004-06-01

    Anti-basal ganglia antibodies (ABGA) have been associated with movement disorders (usually tics and chorea) and psychiatric disturbance in children. This report describes five adult and adolescent patients (one male, four females; mean age of onset, 16 years (range, 13-35)) who presented subacutely with a clinical syndrome dominated by dystonia and had ABGA binding to antigens of similar molecular weights to those seen in Sydenham's chorea. Three patients had a clear history of respiratory infection before the onset of their symptoms. Three patients received immunosuppressive treatment, with three showing a notable reduction in symptoms. It is hypothesised that dystonia in adults or adolescents may be part of the clinical spectrum of the post-infectious syndrome associated with ABGA. PMID:15146015

  19. Desalination of Basal Water by Mesoporous Carbons Nanocomposite Membrane.

    PubMed

    Choi, Jeongdong; Ahn, Youngho; Gamal El-Din, Mohamed; Kim, Eun-Sik

    2016-02-01

    The hydro-transportation process used to obtain bitumen from the Alberta oil sands produces large volume of basal depressurization water (BDW), which contains high salt concentrations. In this research, thin-film nanocomposite (TFN) membrane technology applied to treat BDW in lab-scale, and evaluated water properties before and after the treatment. The average rejection ratios of ionic species were 95.2% and 92.8% by TFN membrane (with ordered mesoporous carbons (OMCs)) and thin-film composite (TFC) (without OMCs) membrane, respectively. The turbidity and total dissolved solids (TDS) were completely rejected in all treatment conditions. Interestingly, the water flux of TFN membrane was dramatically increased compared to TFC membrane. The increase of water flux was believed to be caused by the increased membrane surface hydrophilicity and nano-pore effects by the OMCs. PMID:27433734

  20. Microscopic fluorescence spectral analysis of basal cell carcinomas

    NASA Astrophysics Data System (ADS)

    He, Qingli; Lui, Harvey; Zloty, David; Cowan, Bryce; Warshawski, Larry; McLean, David I.; Zeng, Haishan

    2007-05-01

    Background and Objectives. Laser-induced autofluorescence (LIAF) is a promising tool for cancer diagnosis. This method is based on the differences in autofluorescence spectra between normal and cancerous tissues, but the underlined mechanisms are not well understood. The objective of this research is to study the microscopic origins and intrinsic fluorescence properties of basal cell carcinoma (BCC) for better understanding of the mechanism of in vivo fluorescence detection and margin delineation of BCCs on skin patients. A home-made micro- spectrophotometer (MSP) system was used to image the fluorophore distribution and to measure the fluorescence spectra of various microscopic structures and regions on frozen tissue sections. Materials and Methods. BCC tissue samples were obtained from 14 patients undergoing surgical resections. After surgical removal, each tissue sample was immediately embedded in OCT medium and snap-frozen in liquid nitrogen. The frozen tissue block was then cut into 16-μm thickness sections using a cryostat microtome and placed on microscopic glass slides. The sections for fluorescence study were kept unstained and unfixed, and then analyzed by the MSP system. The adjacent tissue sections were H&E stained for histopathological examination and also served to help identify various microstructures on the adjacent unstained sections. The MSP system has all the functions of a conventional microscope, plus the ability of performing spectral analysis on selected micro-areas of a microscopic sample. For tissue fluorescence analysis, 442nm He-Cd laser light is used to illuminate and excite the unstained tissue sections. A 473-nm long pass filter was inserted behind the microscope objective to block the transmitted laser light while passing longer wavelength fluorescence signal. The fluorescence image of the sample can be viewed through the eyepieces and also recorded by a CCD camera. An optical fiber is mounted onto the image plane of the photograph

  1. Dermatocosmetologic aspects of treatment of basal-cell skin cancer

    NASA Astrophysics Data System (ADS)

    Geinitz, A. V.; Stranadko, Ye. F.; Yusupova, Zh. M.; Tkachenko, S. B.

    2005-08-01

    The obtained clinical findings demonstrate excellent results after surgical MSC treatment with the application of modem laser surgical technologies. All the operated patients were under oncologist"s control during 1.5-2.5 years. In 6 cases we observed topical recurrences which needed a repeated intervention. Thus, our experience of applying LPh for surgical treatment of basal-cell carcinomas of the head and neck dem- onstrate that in the analysed cases it is more reasonable to use two models of laser devices different in their physical parameters. These devices are used at different surgical stages so as to provide a precise effect in laser tumour va- porization within the borders of the healthy tissue, to make better vascular coagulation and laser smoothing of wound surface. Immediate, direct and long-term results of modern surgical lasers" application for treating skin BSC almost in all cases give good and excellent cosmetic effect after such intenventions.

  2. The metabolic and mitogenic properties of basal insulin analogues

    PubMed Central

    2013-01-01

    Context Retrospective, observational studies have reported an association between diabetes treatment with insulin and a higher incidence of cancer. Objective Overview the literature for in vitro and in vivo studies of the metabolic and mitogenic properties of basal insulin analogues and assess the implications for clinical use. Methods Relevant studies were identified through PubMed and congress abstract database searches; data on metabolic and mitogenic signalling in relation to insulin treatment of diabetes are included in this review. Results The balance of evidence shows that although some analogues have demonstrated mitogenic potency in some in vitro studies in cancer cell lines, these findings do not translate to the in vivo setting in animals or to the clinical setting in humans. Conclusions The current consensus is that there is no clinical or in vivo evidence to indicate that any commercially available insulin analogue has carcinogenic effects. Large-scale, prospective clinical and observational studies will further establish any potential link. PMID:23373726

  3. Evolutionary Consequences of DNA Methylation in a Basal Metazoan.

    PubMed

    Dixon, Groves B; Bay, Line K; Matz, Mikhail V

    2016-09-01

    Gene body methylation (gbM) is an ancestral and widespread feature in Eukarya, yet its adaptive value and evolutionary implications remain unresolved. The occurrence of gbM within protein-coding sequences is particularly puzzling, because methylation causes cytosine hypermutability and hence is likely to produce deleterious amino acid substitutions. We investigate this enigma using an evolutionarily basal group of Metazoa, the stony corals (order Scleractinia, class Anthozoa, phylum Cnidaria). We show that patterns of coral gbM are similar to other invertebrate species, predicting wide and active transcription and slower sequence evolution. We also find a strong correlation between gbM and codon bias, resulting from systematic replacement of CpG bearing codons. We conclude that gbM has strong effects on codon evolution and speculate that this may influence establishment of optimal codons. PMID:27189563

  4. A descending dopamine pathway conserved from basal vertebrates to mammals

    PubMed Central

    Ryczko, Dimitri; Cone, Jackson J.; Alpert, Michael H.; Goetz, Laurent; Auclair, François; Dubé, Catherine; Parent, Martin; Roitman, Mitchell F.; Alford, Simon; Dubuc, Réjean

    2016-01-01

    Dopamine neurons are classically known to modulate locomotion indirectly through ascending projections to the basal ganglia that project down to brainstem locomotor networks. Their loss in Parkinson’s disease is devastating. In lampreys, we recently showed that brainstem networks also receive direct descending dopaminergic inputs that potentiate locomotor output. Here, we provide evidence that this descending dopaminergic pathway is conserved to higher vertebrates, including mammals. In salamanders, dopamine neurons projecting to the striatum or brainstem locomotor networks were partly intermingled. Stimulation of the dopaminergic region evoked dopamine release in brainstem locomotor networks and concurrent reticulospinal activity. In rats, some dopamine neurons projecting to the striatum also innervated the pedunculopontine nucleus, a known locomotor center, and stimulation of the dopaminergic region evoked pedunculopontine dopamine release in vivo. Finally, we found dopaminergic fibers in the human pedunculopontine nucleus. The conservation of a descending dopaminergic pathway across vertebrates warrants re-evaluating dopamine’s role in locomotion. PMID:27071118

  5. Basal forebrain control of wakefulness and cortical rhythms.

    PubMed

    Anaclet, Christelle; Pedersen, Nigel P; Ferrari, Loris L; Venner, Anne; Bass, Caroline E; Arrigoni, Elda; Fuller, Patrick M

    2015-01-01

    Wakefulness, along with fast cortical rhythms and associated cognition, depend on the basal forebrain (BF). BF cholinergic cell loss in dementia and the sedative effect of anti-cholinergic drugs have long implicated these neurons as important for cognition and wakefulness. The BF also contains intermingled inhibitory GABAergic and excitatory glutamatergic cell groups whose exact neurobiological roles are unclear. Here we show that genetically targeted chemogenetic activation of BF cholinergic or glutamatergic neurons in behaving mice produced significant effects on state consolidation and/or the electroencephalogram but had no effect on total wake. Similar activation of BF GABAergic neurons produced sustained wakefulness and high-frequency cortical rhythms, whereas chemogenetic inhibition increased sleep. Our findings reveal a major contribution of BF GABAergic neurons to wakefulness and the fast cortical rhythms associated with cognition. These findings may be clinically applicable to manipulations aimed at increasing forebrain activation in dementia and the minimally conscious state. PMID:26524973

  6. A descending dopamine pathway conserved from basal vertebrates to mammals.

    PubMed

    Ryczko, Dimitri; Cone, Jackson J; Alpert, Michael H; Goetz, Laurent; Auclair, François; Dubé, Catherine; Parent, Martin; Roitman, Mitchell F; Alford, Simon; Dubuc, Réjean

    2016-04-26

    Dopamine neurons are classically known to modulate locomotion indirectly through ascending projections to the basal ganglia that project down to brainstem locomotor networks. Their loss in Parkinson's disease is devastating. In lampreys, we recently showed that brainstem networks also receive direct descending dopaminergic inputs that potentiate locomotor output. Here, we provide evidence that this descending dopaminergic pathway is conserved to higher vertebrates, including mammals. In salamanders, dopamine neurons projecting to the striatum or brainstem locomotor networks were partly intermingled. Stimulation of the dopaminergic region evoked dopamine release in brainstem locomotor networks and concurrent reticulospinal activity. In rats, some dopamine neurons projecting to the striatum also innervated the pedunculopontine nucleus, a known locomotor center, and stimulation of the dopaminergic region evoked pedunculopontine dopamine release in vivo. Finally, we found dopaminergic fibers in the human pedunculopontine nucleus. The conservation of a descending dopaminergic pathway across vertebrates warrants re-evaluating dopamine's role in locomotion. PMID:27071118

  7. Causes and significance of variation in mammalian basal metabolism.

    PubMed

    Raichlen, David A; Gordon, Adam D; Muchlinski, Magdalena N; Snodgrass, J Josh

    2010-02-01

    Mammalian basal metabolic rates (BMR) increase with body mass, whichs explains approximately 95% of the variation in BMR. However, at a given mass, there remains a large amount of variation in BMR. While many researchers suggest that the overall scaling of BMR with body mass is due to physiological constraints, variation at a given body mass may provide clues as to how selection acts on BMR. Here, we examine this variation in BMR in a broad sample of mammals and we test the hypothesis that, across mammals, body composition explains differences in BMR at a given body mass. Variation in BMR is strongly correlated with variation in muscle mass, and both of these variables are correlated with latitude and ambient temperature. These results suggest that selection alters BMR in response to thermoregulatory pressures, and that selection uses muscle mass as a means to generate this variation. PMID:19730868

  8. Evolutionary Consequences of DNA Methylation in a Basal Metazoan

    PubMed Central

    Dixon, Groves B.; Bay, Line K.; Matz, Mikhail V.

    2016-01-01

    Gene body methylation (gbM) is an ancestral and widespread feature in Eukarya, yet its adaptive value and evolutionary implications remain unresolved. The occurrence of gbM within protein-coding sequences is particularly puzzling, because methylation causes cytosine hypermutability and hence is likely to produce deleterious amino acid substitutions. We investigate this enigma using an evolutionarily basal group of Metazoa, the stony corals (order Scleractinia, class Anthozoa, phylum Cnidaria). We show that patterns of coral gbM are similar to other invertebrate species, predicting wide and active transcription and slower sequence evolution. We also find a strong correlation between gbM and codon bias, resulting from systematic replacement of CpG bearing codons. We conclude that gbM has strong effects on codon evolution and speculate that this may influence establishment of optimal codons. PMID:27189563

  9. Ancestral reproductive structure in basal kelp Aureophycus aleuticus

    PubMed Central

    Kawai, Hiroshi; Hanyuda, Takeaki; Ridgway, L. Michelle; Holser, Karin

    2013-01-01

    Laminarialean species (so-called kelps) are the largest photosynthetic organisms in aquatic environments, constituting significant ecological components of coastal ecosystems. The largest kelps such as Macrocystis exhibit differentiation between stipe and blade, as well as buoyancy to maintain the distal portion at the water's surface for photosynthesis, while bearing reproductive structures only near the base on special blades (sporophylls). There is a considerable gap between basic kelps such as Chorda and derived kelps, and the evolution of kelp specialization remains unclear. Here we report novel reproductive adaptations in the recently discovered species Aureophycus aleuticus; unlike any known kelps, A. aleuticus forms zoidangia only on the expanded, disc-shaped holdfast. Molecular phylogeny suggests that A. aleuticus is most basal among derived kelps. Because Aureophycus lacks any of the elaborate anatomical structures found in other derived kelps, we suggest that it exhibits some of the most ancestral morphological features of kelps. PMID:23966101

  10. Gorlin's syndrome, or nevoid basal cell carcinoma syndrome.

    PubMed Central

    Fitzpatrick, P. J.; Thompson, G. A.

    1982-01-01

    Gorlin's syndrome is a condition inherited in an autosomal dominant fashion. It involves many organs, but principally affects the skin, skeleton, and endocrine and nervous systems. The most common features are multiple nervi and basal cell carcinomas of the skin, benign jaw cysts, dyskeratotic pits in the palms and soles, rib and vertebral abnormalities, brachymetacarpalism, and calcification of the falx cerebri. In 14 patients, 4 of whom belonged to one family, the age at the time of diagnosis ranged from 11 to 63 years. Ten patients are alive, but five are severely disfigured by carcinomas. Two patients died of complications resulting from uncontrolled tumours, and two died of other cancers. New skin tumours constantly develop; small ones can be excised, but large ones require extensive surgery with or without radiotherapy. Images FIG. 1 FIG. 2 FIG. 3 FIG. 4 FIG. 5 FIG. 6 FIG. 7 FIG. 9 FIG. 10 FIG. 11 PMID:7116263

  11. Basal forebrain control of wakefulness and cortical rhythms

    PubMed Central

    Anaclet, Christelle; Pedersen, Nigel P.; Ferrari, Loris L.; Venner, Anne; Bass, Caroline E.; Arrigoni, Elda; Fuller, Patrick M.

    2015-01-01

    Wakefulness, along with fast cortical rhythms and associated cognition, depend on the basal forebrain (BF). BF cholinergic cell loss in dementia and the sedative effect of anti-cholinergic drugs have long implicated these neurons as important for cognition and wakefulness. The BF also contains intermingled inhibitory GABAergic and excitatory glutamatergic cell groups whose exact neurobiological roles are unclear. Here we show that genetically targeted chemogenetic activation of BF cholinergic or glutamatergic neurons in behaving mice produced significant effects on state consolidation and/or the electroencephalogram but had no effect on total wake. Similar activation of BF GABAergic neurons produced sustained wakefulness and high-frequency cortical rhythms, whereas chemogenetic inhibition increased sleep. Our findings reveal a major contribution of BF GABAergic neurons to wakefulness and the fast cortical rhythms associated with cognition. These findings may be clinically applicable to manipulations aimed at increasing forebrain activation in dementia and the minimally conscious state. PMID:26524973

  12. The dopaminergic projection system, basal forebrain macrosystems, and conditioned stimuli

    PubMed Central

    Zahm, Daniel S.

    2011-01-01

    This review begins with a description of some problems that in recent years have beset an influential circuit model of fear-conditioning and goes on to look at neuroanatomy that might subserve conditioning viewed in a broader perspective, including not only fear, but also appetitive, conditioning. The paper then focuses on basal forebrain functional-anatomical systems, or macrosystems, as they have come to be called, which Lennart Heimer and colleagues described beginning in the 1970’s. Yet more specific attention is then given to the relationships of the dorsal and ventral striatopallidal systems and extended amygdala with the dopaminergic mesotelencephalic projection systems, culminating with the hypothesis that all macrosystems contribute to behavioral conditioning. PMID:18204412

  13. Novel Hedgehog pathway targets against basal cell carcinoma

    SciTech Connect

    Tang, Jean Y. So, P.-L.; Epstein, Ervin H.

    2007-11-01

    The Hedgehog signaling pathway plays a key role in directing growth and patterning during embryonic development and is required in vertebrates for the normal development of many structures, including the neural tube, axial skeleton, skin, and hair. Aberrant activation of the Hedgehog (Hh) pathway in adult tissue is associated with the development of basal cell carcinoma (BCC), medulloblastoma, and a subset of pancreatic, gastrointestinal, and other cancers. This review will provide an overview of what is known about the mechanisms by which activation of Hedgehog signaling leads to the development of BCCs and will review two recent papers suggesting that agents that modulate sterol levels might influence the Hh pathway. Thus, sterols may be a new therapeutic target for the treatment of BCCs, and readily available agents such as statins (HMG-CoA reductase inhibitors) or vitamin D might be helpful in reducing BCC incidence.

  14. Auditory Cortex Basal Activity Modulates Cochlear Responses in Chinchillas

    PubMed Central

    León, Alex; Elgueda, Diego; Silva, María A.; Hamamé, Carlos M.; Delano, Paul H.

    2012-01-01

    Background The auditory efferent system has unique neuroanatomical pathways that connect the cerebral cortex with sensory receptor cells. Pyramidal neurons located in layers V and VI of the primary auditory cortex constitute descending projections to the thalamus, inferior colliculus, and even directly to the superior olivary complex and to the cochlear nucleus. Efferent pathways are connected to the cochlear receptor by the olivocochlear system, which innervates outer hair cells and auditory nerve fibers. The functional role of the cortico-olivocochlear efferent system remains debated. We hypothesized that auditory cortex basal activity modulates cochlear and auditory-nerve afferent responses through the efferent system. Methodology/Principal Findings Cochlear microphonics (CM), auditory-nerve compound action potentials (CAP) and auditory cortex evoked potentials (ACEP) were recorded in twenty anesthetized chinchillas, before, during and after auditory cortex deactivation by two methods: lidocaine microinjections or cortical cooling with cryoloops. Auditory cortex deactivation induced a transient reduction in ACEP amplitudes in fifteen animals (deactivation experiments) and a permanent reduction in five chinchillas (lesion experiments). We found significant changes in the amplitude of CM in both types of experiments, being the most common effect a CM decrease found in fifteen animals. Concomitantly to CM amplitude changes, we found CAP increases in seven chinchillas and CAP reductions in thirteen animals. Although ACEP amplitudes were completely recovered after ninety minutes in deactivation experiments, only partial recovery was observed in the magnitudes of cochlear responses. Conclusions/Significance These results show that blocking ongoing auditory cortex activity modulates CM and CAP responses, demonstrating that cortico-olivocochlear circuits regulate auditory nerve and cochlear responses through a basal efferent tone. The diversity of the obtained effects

  15. Body Composition and Basal Metabolic Rate in Women with Type 2 Diabetes Mellitus

    PubMed Central

    de Figueiredo Ferreira, Marina; Detrano, Filipe; Coelho, Gabriela Morgado de Oliveira; Barros, Maria Elisa; Serrão Lanzillotti, Regina; Firmino Nogueira Neto, José; Portella, Emilson Souza; Serrão Lanzillotti, Haydée; Soares, Eliane de Abreu

    2014-01-01

    Objective. The aim of this study was to determine which of the seven selected equations used to predict basal metabolic rate most accurately estimated the measured basal metabolic rate. Methods. Twenty-eight adult women with type 2 diabetes mellitus participated in this cross-sectional study. Anthropometric and biochemical variables were measured as well as body composition (by absorptiometry dual X-ray emission) and basal metabolic rate (by indirect calorimetry); basal metabolic rate was also estimated by prediction equations. Results. There was a significant difference between the measured and the estimated basal metabolic rate determined by the FAO/WHO/UNU (Pvalue < 0.021) and Huang et al. (Pvalue ≤ 0.005) equations. Conclusion. The calculations using Owen et al's. equation were the closest to the measured basal metabolic rate. PMID:25436144

  16. Enzyme Activities of Starch and Sucrose Pathways and Growth of Apical and Basal Maize Kernels 1

    PubMed Central

    Ou-Lee, Tsai-Mei; Setter, Tim Lloyd

    1985-01-01

    Apical kernels of maize (Zea mays L.) ears have smaller size and lower growth rates than basal kernels. To improve our understanding of this difference, the developmental patterns of starch-synthesis-pathway enzyme activities and accumulation of sugars and starch was determined in apical- and basal-kernel endosperm of greenhouse-grown maize (cultivar Cornell 175) plants. Plants were synchronously pollinated, kernels were sampled from apical and basal ear positions throughout kernel development, and enzyme activities were measured in crude preparations. Several factors were correlated with the higher dry matter accumulation rate and larger mature kernel size of basal-kernel endosperm. During the period of cell expansion (7 to 19 days after pollination), the activity of insoluble (acid) invertase and sucose concentration in endosperm of basal kernels exceeded that in apical kernels. Soluble (alkaline) invertase was also high during this stage but was the same in endosperm of basal and apical kernels, while glucose concentration was higher in apical-kernel endosperm. During the period of maximal starch synthesis, the activities of sucrose synthase, ADP-Glc-pyrophosphorylase, and insoluble (granule-bound) ADP-Glc-starch synthase were higher in endosperm of basal than apical kernels. Soluble ADP-Glc-starch synthase, which was maximal during the early stage before starch accumulated, was the same in endosperm from apical and basal kernels. It appeared that differences in metabolic potential between apical and basal kernels were established at an early stage in kernel development. PMID:16664503

  17. Foot formation in Hydra: a novel gene, anklet, is involved in basal disk formation.

    PubMed

    Amimoto, Yasuko; Kodama, Rie; Kobayakawa, Yoshitaka

    2006-05-01

    We isolated a novel gene by a differential-display RT-PCR method comparing basal disk tissue and peduncle tissue in a species of Hydra, Pelmatohydra robusta, and we referred to it as anklet. The putative anklet product has a signal sequence in its N-terminus, and it has one MAC/PF domain and one EGF domain. In normal hydra, the expression of anklet was restricted in the periphery of the basal disk and the lowest region of the peduncle. In foot-regenerating animals, anklet was first expressed in the newly differentiated basal disk gland cells at the regenerating basal end, and then expression became restricted at the periphery of the regenerated basal disk and in the lowest region of the peduncle. This spatially specific expression pattern suggested that the product of the anklet gene plays a role in basal disk formation. We therefore examined the role played by the protein product of the anklet gene by suppressing the transcription level of anklet using an RNA-mediated interference (RNAi) method. Suppression of the level of expression of the anklet gene led to a decrease in basal disk size in normal hydra, and to a delay in basal disk regeneration in foot-amputated animals. These results suggested that anklet is involved in the formation and maintenance of the basal disk in hydra. PMID:16644190

  18. Entosiphon sulcatum (Euglenophyceae): flagellar roots of the basal body complex and reservoir region

    SciTech Connect

    Solomon, J.A.; Walne, P.L.; Kivic, P.A.

    1987-03-01

    The flagellar root system of Entosiphon sulcatum (Dujardin) Stein (Euglenophyceae) is described and compared with kinetoplastid and other euglenoid systems. An asymmetric pattern of three microtubular roots, one between the two flagellar basal bodies and one on either side (here called the intermediate, dorsal, and ventral roots), is consistent within the euglenoid flagellates studied thus far. The dorsal root is associated with the basal body of the anterior flagellum (F1) and lies on the left dorsal side of the basal body complex. Originating between the two flagellar basal bodies, and associated with the basal body of the trailing flagellum (F2), the intermediate root is morphologically distinguished by fibrils interconnecting the individual microtubules to one another and to the overlying reservoir membrane. The intermediate root is often borne on a ridge projecting into the reservoir. The ventral root originates near the F2 basal body and lies on the right ventral side of the cell. Fibrillar connections link the membrane of F2 with the reservoir membrane at the reservoir-canal transition level. A large cross-banded fiber joins the two flagellar basal bodies, and a series of smaller striated fibers links the anterior accessory and flagellar basal bodies. Large nonstriated fibers extend from the basal body complex posteriorly into the cytoplasm.

  19. Is Hazardous Waste Injection into Basal Aquifers a Good Idea?

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Person, M. A.; Rupp, J.; Celia, M. A.; Gable, C. W.; Bowen, B. B.; Mozley, P. S.; Evans, J. P.; Dewers, T. A.

    2012-12-01

    The recent induced M3.8 - M5.5 seismic events across the midcontinent, USA have raised concern regarding regulations for hazardous waste injection. It is also important to note that in the midcontinent region, the Illinois Basin is the main target for storing CO2 up to 1 million metric tons over a 3-year period in the CCS project of DOE. Here we present a hydrogeologic-geomechanical sensitivity study using a hybrid analytic-numerical cross-sectional model to assess a wide variety of possible failure scenarios within crystalline rocks. The hydrostratigraphic framework model we used in this study is based on the geology of the Illinois Basin. The model includes 2.8 km thick Paleozoic sedimentary aquifers and confining units underlain by 4 km of bedrock. We represented injection at 1000 gallons per minute (3785 liters per minute) into a basal sandstone aquifer (Mt. Simon Sandstone) as well as the overlying carbonate and siliciclastic reservoirs (middle aquifer: Knox Dolomite, St. Peter Sandstone, upper Ordovician Carbonates). In some scenarios, we included high/low permeability vertical and sub-horizontal thrust faults. Deviatoric pore pressures from the model were used to estimate failure along critically stressed faults within the bedrock. For a basement permeability between 10-15 m2 to 10-16 m2, injection into the basal aquifer (Mt. Simon sandstone) resulted in a failure envelop within the crystalline basement to depths of about 1.4 - 4 km and extending laterally up to 6 km. Including a transmissive vertical normal fault increased the depth of the failure envelope to 4 km below the base of the sedimentary pile. If a 108 order of magnitude permeability contrast exists between the thrust fault (10-10 m2) and basement rocks (10-18 m2), then pore pressures can propagate along a sub-horizontal fault about 12 km from the injection well. For middle aquifer injection, the presence of a bottom seal (Eau Claire Formation) has a prophylactic effect, preventing downward

  20. Basal entrainment by Newtonian gravity-driven flows

    NASA Astrophysics Data System (ADS)

    Bates, Belinda; Andreini, Nicolas; Ancey, Christophe

    2016-04-01

    Gravity-driven flows can erode the bed along which they descend and increase their mass by a factor of 10 or more. This process is called basal entrainment. Although documented by field observations and laboratory experiments, it remains poorly understood. We look into this issue by studying eroding dam-break waves. More specifically we would like to determine what happens when a viscous gravity-driven flow generated by releasing a fixed volume of incompressible Newtonian fluid encounters a stationary erodible layer (composed of fluid with the same density and viscosity). Models based on depth-averaged mass and momentum balance equations deal with bed-flow interfaces as shock waves. In contrast, we use an approach involving the long-wave approximation of the Navier-Stokes equations (lubrication theory), and in this context, bed-flow interfaces are acceleration waves that move quickly across thin stationary layers. The incoming flow digs down into the bed, pushing up downstream material, thus advancing the flow front. Extending the method used by Huppert [J. Fluid Mech. 121, 43--58 (1982)] for modelling viscous dam-break waves, we end up with a nonlinear diffusion equation for the flow depth, which is solved numerically. Theory is compared with experimental results. Excellent agreement is found in the limit of low Reynolds numbers (i.e., for flow Reynolds numbers lower than 20) for the front position over time and flow depth profile. The Newtonian model has sometimes been used to describe the flow behaviour of natural materials such as snow and debris suspensions, but the majority of existing approaches rely on more elaborate constitutive equations. So there is no direct application of the results presented here to real flow conditions. Yet, our study sheds light on the mechanisms involved in basal entrainment. We provide evidence that the whole layer of loose material is entrained quickly once the flow makes contact with the erodible layer. As this process occurs

  1. Hydrologically Induced Basal Slip Triggers Greenland Supraglacial Lake Drainages

    NASA Astrophysics Data System (ADS)

    Stevens, L. A.; Behn, M. D.; McGuire, J. J.; Das, S. B.; Joughin, I. R.; Herring, T.; Shean, D. E.; King, M. A.

    2014-12-01

    We investigate what triggers the rapid drainage of a large supraglacial lake on the western margin of the Greenland Ice Sheet using a Network Inversion Filter (NIF) (Segall and Matthews, 1997) to invert a dense local network of GPS observations over three summers (2011-2013). The NIF is used to determine the spatiotemporal variability in ice sheet behavior (1) prior to lake drainage, and in response to (2) vertical hydro-fracture crack propagation and closure, (3) the opening of a horizontal cavity at the ice-sheet bed that accommodates the rapid injection of melt-water, and (4) extra basal slip due to enhanced lubrication. The NIF also allows us to infer the distribution of melt-water at the ice-sheet bed before, during, and after drainage. Our data show that the opening and propagation of each summer's lake-draining hydro-fracture is preceded by a local stress perturbation associated with ice sheet uplift and enhanced slip above pre-drainage background velocities. Within <1 day after the onset of each precursor, a vertical crack propagates through the lake basin and the lake drains rapidly (<5 hours). The NIF shows that the precursors are not associated with slow propagation of the lake draining hydrofracture, but rather pre-existing crevasses and/or moulins, which allow substantial amounts of melt-water to reach the bed and activate enhanced basal slip up to a day before hydro-fracture crack initiation. Identification of these precursors combined with the fact that drainages are observed to occur across a range of lake volumes and geometries, suggests that lakes do not spontaneously hydro-fracture once they surpass a specific threshold despite the numerous healed hydro-fracture cracks present within the lake basin from the prior years' drainage events. These results have implications for rapid drainage of supraglacial lakes in less crevassed, interior regions of the Greenland Ice Sheet, as well as the rapid collapse of Antarctic ice shelves through melt pond

  2. Protracted Crystallization of a Dense Basal Magma Ocean

    NASA Astrophysics Data System (ADS)

    Labrosse, S.; Hernlund, J. W.

    2006-12-01

    The presence of silicate melt in a thin layer at the base of Earth's mantle was proposed by Williams and Garnero (1996) to explain the ultralow-velocity zone. Recent ab initio calculations by Stixrude and Karki (2005) suggest that an Fe-enriched silicate melt will be gravitationally stable at the bottom of the mantle. Using energy balances and regional-scale numerical models of convection in the lowermost mantle, we investigate the conditions necessary for the survival of such a melt layer in a cooling earth and its implications for core-mantle thermal coupling. The lifetime of a basal melt layer τ_c is controlled by the balance between heat transfer across the solid mantle and heat capacity of the core times the temperature decrement Δ T_c required to entirely freeze the melt layer. Δ T_c depends on the phase diagram and can also change depending upon whether the layer undergoes bulk or fractional crystallization. In contrast to the short lifetime of the surface magma ocean (~ 10 \\mathrm{Myr}), τ_c is plausibly of order several billion years, with longer lifetimes permitted if the layer undergoes fractional crystallization. Fluctuations of heat flow by mantle convection induce fluctuations in the rate of crystallization which in turn buffers core-mantle heat transfer due to the diffusive adjustment time of the boundary layer at the base of the solid mantle. This could help the dynamo to survive periods of low heat flow across the mantle. Fractional crystallization of the basal melt layer (and subsequent Fe enrichment) could lead to a correlated chemical evolution in the crystallizing solids which, after some time, may become too dense to be entrained by solid state convection in the overlying mantle. This denser material tends to accumulate at the base of up-welling mantle currents and is underlain by material that is naturally buffered to the solidus temperature throughout the lifetime of the melt layer, perhaps providing a simple way to explain the presence

  3. Landslide Basal Friction as Measured by Seismic Waves

    NASA Astrophysics Data System (ADS)

    Brodsky, E. E.; Gordeev, E.

    2004-12-01

    Dynamical predictions of landslide runout require measurements of the basal friction. We present the first seismically determined bounds on the frictional coefficients for three large volcanic landslides. A landslide generates seismic waves by both shearing and loading the surface as the mass moves from a steep to a shallow slope. The effective force system is a horizontal single force. The amplitude of the seismic waves is proportional to the force drop during the landslide, just as during an earthquake the seismic wave amplitude is proportional to the seismic moment, i.e., the force drop multiplied by the source dimension. For landslides we know an additional variable that is unknown for the earthquake case. We know the gravitational driving force of the landslide while the magnitude of the tectonic forces that drive earthquakes are generally unknown. Therefore, we can find the absolute value of the frictional force for landslides whereas we are unable to perform this calculation for earthquakes. We studied three landslides (Bezymianny, Russia 1956, Sheveluch, Russia 1964 and Mount St. Helens, USA 1980) that were all followed immediately by eruptions. The landslide masses vary by a factor of 5. We test the data against the hypothesis of a constant value of apparent friction. The apparent friction μ app is defined as the ratio of the amplitude of the horizontal single force to the weight of the landslide. Since the Mount St. Helens seismic source is very well-constrained, we use the amplitude of this landslide force drop as a starting point. We calculated the value of μ app for Mount St. Helens using previous seismic results and the geological data. We then test whether or not the other two landslides are consistent with the same value of μ app. We use teleseismic and regional seismic data to show that all three landslides are consistent with an apparent coefficient of friction of 0.2 which corresponds to an actual areally-averaged frictional coefficient of 0

  4. Channelised Subglacial Hydrology Modulates West Antarctic Ice Stream Basal Conditions and Flow

    NASA Astrophysics Data System (ADS)

    Siegert, M. J.; Ross, N.; Schroeder, D. M.

    2014-12-01

    Ice-sheet models show a coincidence between ice flux and basal water-flow maxima, as water at the bed of an ice sheets acts generally to lubricate the basal interface. Hydrological flow paths support this view with ice and basal-water drainage basins being well-aligned. At the scale of an individual ice stream, however, we reveal a significant offset of this alignment. Airborne geophysical data across the trunk of the Institute Ice Stream reveal how subglacial hydrology acts to subdue ice flow in two ways: first, by removing basal sediment, which decreases opportunity for the deformation of basal material and increases basal roughness; and, second, by reducing basal water pressures. The macro flow of basal water beneath the ice stream is known well from high-resolution bed elevation data and satellite imagery, which reveal well-organised water flow along the Robin Subglacial Basin, terminating at the grounding line as a channel carving upwards into the adjacent ice shelf. The highest ice flow is offset from this channelized zone, however. Maximum velocities are located where the bed is very smooth and radio-echo returns are strong; consistent with a dilated weak sedimentary material at the ice stream bed. The geophysical evidence is consistent with the removal of basal sediment from the deepest regions of the Robin Subglacial Basin by the action of water and illustrates how accumulation of sedimentary material from ice streams is not necessary a precise locator for maximum ice-flow velocities at the scale of individual ice streams. The figure shows a radar section across the Institute Ice Stream, West Antarctica, revealing two modes of basal environment. One is flat and smooth, indicative of a soft wet bed. The other is rougher, as a consequence of the removal of basal material and water channelisation. This latter region is located in the deepest regions of the Robin Subglacial Basin. The former region is located beneath the highest ice flow speeds.

  5. Plasticity of basal cells during postnatal development in the rat epididymis

    PubMed Central

    Shum, Winnie W C; Hill, Eric; Brown, Dennis; Breton, Sylvie

    2014-01-01

    Our previous study has shown that basal cells sense luminal factors by forming a narrow body projection that can cross epithelial tight junctions. As a first step toward characterizing the structural plasticity of basal cells, in this study, we followed their appearance and morphology in the rat epididymis and vas deferens (VD) during postnatal development and examined their modulation by androgens in adulthood. Immunofluorescence labeling for cytokeratin 5 showed that basal cells are absent at birth. They progressively appear in a retrograde manner from the VD and cauda epididymis to the initial segments during the postnatal weeks PNW1–3. At the onset of differentiation, basal cells are in contact with the lumen and their nucleus is located at the same level as that of adjacent epithelial cells. Basal cells then position their nucleus to the base of the epithelium, and while some are still in contact with the lumen, others have a ‘dome-shaped’ appearance. At PNW5–6, basal cells form a loose network at the base of the epithelium, and luminal-reaching basal cells are rarely detected. The arrival of spermatozoa during PNW7–8 did not trigger the development of projections in basal cells. However, cells with a narrow luminal-reaching projection began to reappear between PNW8 and PNW12 in the corpus and the cauda. Treatment with flutamide from PNW10 to PNW12 significantly reduced the number of luminal-reaching basal cell projections. In summary, basal cells exhibit significant structural plasticity during differentiation. Fewer apical-reaching projections were detected after flutamide treatment in adulthood, indicating the role of androgens in the luminal-sensing function of basal cells. PMID:23960170

  6. Basal Murphy belt and Chilhowee Group -- Sequence stratigraphic comparison

    SciTech Connect

    Aylor, J.G. Jr. . Dept. of Geology)

    1994-03-01

    The lower Murphy belt in the central western Blue Ridge is interpreted to be correlative to the Early Cambrian Chilhowee Group of the westernmost Blue Ridge and Appalachian fold and thrust belt. Basal Murphy belt depositional sequence stratigraphy represents a second-order, type-2 transgressive systems tract initiated with deposition of lowstand turbidites of the Dean Formation. These transgressive deposits of the Nantahala and Brasstown Formations are interpreted as middle to outer continental shelf deposits. Cyclic and stacked third-order regressive, coarsening upwards sequences of the Nantahala Formation display an overall increase in feldspar content stratigraphically upsection. These transgressive siliciclastic deposits are interpreted to be conformably overlain by a carbonate highstand systems tract of the Murphy Marble. Palinspastic reconstruction indicates that the Nantahala and Brasstown Formations possibly represent a basinward extension of up to 3 km thick siliciclastic wedge. The wedge tapers to the southwest along the strike of the Murphy belt at 10[degree] and thins northwestward to 2 km in the Tennessee depocenter where it is represented by the Chilhowee Group. The Murphy belt basin is believed to represent a transitional rift-to-drift facies deposited on the lower plate of the southern Blue Ridge rift zone.

  7. Discovery of alpha-defensins in basal mammals.

    PubMed

    Lynn, David J; Bradley, Daniel G

    2007-01-01

    Alpha-defensins are essential molecules of the innate immune system that have broad spectrum antimicrobial activity against a range of bacteria and viruses. To date, alpha-defensins have only been identified in the Euarchontoglires branch of the mammals. This has led to speculation that alpha-defensins may be specific to this group, a somewhat surprising finding, given their importance in the immune system. The mammalian genome project provided us with the opportunity to search for alpha-defensins in previously unexamined mammalian superorders. Using hidden Markov model (HMM) profile searching, we report the discovery of alpha-defensins in the African savanna elephant, the lesser hedgehog tenrec, and the nine-banded armadillo genomes representing two of the most basal mammalian superorders, Afrotheria and Xenarthra. Furthermore, we identify an alpha-defensin-like gene in the gray short-tailed opossum, suggesting that alpha-defensins may have evolved much earlier than previously thought, before the divergence of placental mammals and marsupials approximately 130 mya. PMID:17367857

  8. Antipathetic magnesium-manganese relationship in basal metalliferous sediments

    USGS Publications Warehouse

    Bloch, S.

    1981-01-01

    Basal metalliferous sediments from sites 77B, 80 and 81 of the Deep Sea Drilling Project represent mixtures of pelagic clay, biogenic ooze, and a metalliferous component of hydrothermal origin. The metalliferous end-member of the sediments displays a strong inverse relationship (r = -0.88) between Mg and Mn. Mg is most likely tied up in an X-ray amorphous Mg-silicate ("sepiolite"), whereas Mn occurs almost exclusively in an oxide phase. Precipitation of the Mg-rich phase is favored by high flow rates and limited mixing of the hydrothermal end-member (source of silica) with seawater (source of Mg). Under those conditions much of the hydrothermal Mn2+, with its slow oxidation kinetics, may escape to the free water column. In contrast, in highly-diluted hydrothermal fluids, which provide a source solution for Mn-rich sediments, dissolved silica is diluted below saturation with respect to "sepiolite". The separation of the Mn and Mg phases may be further compounded by hydraulic fractionation. ?? 1981.

  9. Sonic hedgehog signaling in Basal cell nevus syndrome.

    PubMed

    Athar, Mohammad; Li, Changzhao; Kim, Arianna L; Spiegelman, Vladimir S; Bickers, David R

    2014-09-15

    The hedgehog (Hh) signaling pathway is considered to be a major signal transduction pathway during embryonic development, but it usually shuts down after birth. Aberrant Sonic hedgehog (Shh) activation during adulthood leads to neoplastic growth. Basal cell carcinoma (BCC) of the skin is driven by this pathway. Here, we summarize information related to the pathogenesis of this neoplasm, discuss pathways that crosstalk with Shh signaling, and the importance of the primary cilium in this neoplastic process. The identification of the basic/translational components of Shh signaling has led to the discovery of potential mechanism-driven druggable targets and subsequent clinical trials have confirmed their remarkable efficacy in treating BCCs, particularly in patients with nevoid BCC syndrome (NBCCS), an autosomal dominant disorder in which patients inherit a germline mutation in the tumor-suppressor gene Patched (Ptch). Patients with NBCCS develop dozens to hundreds of BCCs due to derepression of the downstream G-protein-coupled receptor Smoothened (SMO). Ptch mutations permit transposition of SMO to the primary cilium followed by enhanced expression of transcription factors Glis that drive cell proliferation and tumor growth. Clinical trials with the SMO inhibitor, vismodegib, showed remarkable efficacy in patients with NBCCS, which finally led to its FDA approval in 2012. PMID:25172843

  10. Time-resolved multiphoton imaging of basal cell carcinoma

    NASA Astrophysics Data System (ADS)

    Cicchi, R.; Sestini, S.; De Giorgi, V.; Stambouli, D.; Carli, P.; Massi, D.; Pavone, F. S.

    2007-02-01

    We investigated human cutaneous basal cell carcinoma ex-vivo samples by combined time resolved two photon intrinsic fluorescence and second harmonic generation microscopy. Morphological and spectroscopic differences were found between malignant skin and corresponding healthy skin tissues. In comparison with normal healthy skin, cancer tissue showed a different morphology and a mean fluorescence lifetime distribution slightly shifted towards higher values. Topical application of delta-aminolevulinic acid to the lesion four hours before excision resulted in an enhancement of the fluorescence signal arising from malignant tissue, due to the accumulation of protoporphyrines inside tumor cells. Contrast enhancement was prevalent at tumor borders by both two photon fluorescence microscopy and fluorescence lifetime imaging. Fluorescence-based images showed a good correlation with conventional histopathological analysis, thereby supporting the diagnostic accuracy of this novel method. Combined morphological and lifetime analysis in the study of ex-vivo skin samples discriminated benign from malignant tissues, thus offering a reliable, non-invasive tool for the in-vivo analysis of inflammatory and neoplastic skin lesions.

  11. Modeling basal ganglia for understanding Parkinsonian reaching movements.

    PubMed

    Magdoom, K N; Subramanian, D; Chakravarthy, V S; Ravindran, B; Amari, Shun-Ichi; Meenakshisundaram, N

    2011-02-01

    We present a computational model that highlights the role of basal ganglia (BG) in generating simple reaching movements. The model is cast within the reinforcement learning (RL) framework with correspondence between RL components and neuroanatomy as follows: dopamine signal of substantia nigra pars compacta as the temporal difference error, striatum as the substrate for the critic, and the motor cortex as the actor. A key feature of this neurobiological interpretation is our hypothesis that the indirect pathway is the explorer. Chaotic activity, originating from the indirect pathway part of the model, drives the wandering, exploratory movements of the arm. Thus, the direct pathway subserves exploitation, while the indirect pathway subserves exploration. The motor cortex becomes more and more independent of the corrective influence of BG as training progresses. Reaching trajectories show diminishing variability with training. Reaching movements associated with Parkinson's disease (PD) are simulated by reducing dopamine and degrading the complexity of indirect pathway dynamics by switching it from chaotic to periodic behavior. Under the simulated PD conditions, the arm exhibits PD motor symptoms like tremor, bradykinesia and undershooting. The model echoes the notion that PD is a dynamical disease. PMID:21105828

  12. Origins of basal ganglia output signals in singing juvenile birds

    PubMed Central

    Pidoux, Morgane; Bollu, Tejapratap; Riccelli, Tori

    2014-01-01

    Across species, complex circuits inside the basal ganglia (BG) converge on pallidal output neurons that exhibit movement-locked firing patterns. Yet the origins of these firing patterns remain poorly understood. In songbirds during vocal babbling, BG output neurons homologous to those found in the primate internal pallidal segment are uniformly activated in the tens of milliseconds prior to syllable onsets. To test the origins of this remarkably homogenous BG output signal, we recorded from diverse upstream BG cell types during babbling. Prior to syllable onsets, at the same time that internal pallidal segment-like neurons were activated, putative medium spiny neurons, fast spiking and tonically active interneurons also exhibited transient rate increases. In contrast, pallidal neurons homologous to those found in primate external pallidal segment exhibited transient rate decreases. To test origins of these signals, we performed recordings following lesion of corticostriatal inputs from premotor nucleus HVC. HVC lesions largely abolished these syllable-locked signals. Altogether, these findings indicate a striking homogeneity of syllable timing signals in the songbird BG during babbling and are consistent with a role for the indirect and hyperdirect pathways in transforming cortical inputs into BG outputs during an exploratory behavior. PMID:25392171

  13. Subregional Basal Forebrain Atrophy in Alzheimer's Disease: A Multicenter Study

    PubMed Central

    Kilimann, Ingo; Grothe, Michel; Heinsen, Helmut; Alho, Eduardo Joaquim Lopez; Grinberg, Lea; Amaro, Edson; dos Santos, Gláucia Aparecida Bento; da Silva, Rafael Emídio; Mitchell, Alex J.; Frisoni, Giovanni B.; Bokde, Arun L.W.; Fellgiebel, Andreas; Filippi, Massimo; Hampel, Harald; Klöppel, Stefan; Teipel, Stefan J.

    2014-01-01

    Histopathological studies in Alzheimer's disease (AD) suggest severe and region-specific neurodegeneration of the basal forebrain cholinergic system (BFCS). Here, we studied the between-center reliability and diagnostic accuracy of MRI-based BFCS volumetry in a large multicenter data set, including participants with prodromal (n = 41) or clinically manifest AD (n = 134) and 148 cognitively healthy controls. Atrophy was determined using voxel-based and region-of-interest based analyses of high-dimensionally normalized MRI scans using a newly created map of the BFCS based on postmortem in cranio MRI and histology. The AD group showed significant volume reductions of all subregions of the BFCS, which were most pronounced in the posterior nucleus basalis Meynert (NbM). The mild cognitive impairment-AD group showed pronounced volume reductions in the posterior NbM, but preserved volumes of anterior-medial regions. Diagnostic accuracy of posterior NbM volume was superior to hippocampus volume in both groups, despite higher multicenter variability of the BFCS measurements. The data of our study suggest that BFCS morphometry may provide an emerging biomarker in AD. PMID:24503619

  14. Neglected Basal Cell Carcinomas in the 21st Century

    PubMed Central

    Varga, Erika; Korom, Irma; Raskó, Zoltán; Kis, Erika; Varga, János; Oláh, Judit; Kemény, Lajos

    2011-01-01

    Although tumors on the surface of the skin are considered to be easily recognizable, neglected advanced skin neoplasms are encountered even in the 21st century. There can be numerous causes of the delay in the diagnosis: fear of the diagnosis and the treatment, becoming accustomed to a slowly growing tumor, old age, a low social milieu, and an inadequate hygienic culture are among the factors leading some people not to seek medical advice. The treatment of such advanced neoplasms is usually challenging. The therapy of neglected cases demands an individual multidisciplinary approach and teamwork. Basal cell carcinoma (BCC), the most common cutaneous tumor, usually develops in the elderly, grows slowly, and has an extremely low metastatic potential; these factors are suggesting that BCCs might well be the “ideal candidates” for neglected tumors. Five neglected advanced cases of BCC were diagnosed in our dermatological institute between 2000 and 2009. The clinical characteristics and treatment modalities of these neoplasms are discussed, together with the possible causes of the neglect. PMID:21151693

  15. Clinical outcome of surgical treatment for periorbital basal cell carcinoma.

    PubMed

    Kakudo, Natsuko; Ogawa, Yutaka; Suzuki, Kenji; Kushida, Satoshi; Kusumoto, Kenji

    2009-11-01

    Basal cell carcinoma (BCC) has a predilection for the periorbital region, which is a special, prominent, cosmetic, functional area to protect the eyeball. For squamous cell carcinoma and melanoma, extensive resection with reconstruction is performed. In contrast, for BCC, resection is often confined to a small to medium-sized area, necessitating higher-quality reconstructive surgery. We analyze the surgical outcomes of treatment for periorbital BCC, and evaluate reconstruction method after resection. Forty-nine patients with periorbital BCC had surgery in our hospital over 20 years. Age, gender of the patients, and size, localization, and histology of the tumor, and surgical procedures, and their early and late complications were analyzed retrospectively. BCC was most frequently occurred in the lower lid (55%), followed by inner canthus (19%), upper lid (17%), and outer canthus (9%). The histologic classifications were solid (80%), morphea (7%), mix (7%), superficial (2%), keratotic (2%), and adenoid (2%). Recurrence of the tumor was observed in 2 advanced cases in patients treated with resection of the tumor including surrounding tissue 5 mm from the margin. A rotation advancement cheek flap procedure was most frequently applied. Horizontal shift of the skin was most effective to prevent postoperative lagophthalmos. BCC occurred most frequently in the lower lid within the periorbital area. Rotation advancement of cheek flap with horizontal shift of the skin is most effective procedure in both appearance and function of the eyelid. PMID:19801921

  16. Morphological Spectrum of Basal Cell Carcinoma in Southern Karnataka

    PubMed Central

    Lobo, Flora Dorothy; Naik, Ramdas; Khadilkar, Urmila Niranjan; Kini, Hema; Kini, Ullal Anand

    2016-01-01

    Introduction Basal Cell Carcinoma (BCC) is the most common skin cancer worldwide, which appears over sun-exposed skin as slow-growing, locally invasive lesion that rarely metastasizes. Many phenotypic presentations are possible. BCCs are more common in males and tend to occur in older people. Majority is found on the head and neck. Many histopathological subtypes have been defined including nodular, micronodular, cystic, superficial, pigmented, adenoid, infiltrating, sclerosing, keratotic, infundibulocystic, metatypical, basosquamous and fibroepitheliomatous. Mixed patterns are common. Aim The aim was to study morphological spectrum of BCC in a tertiary care hospital in southern Karnataka. Materials and Methods This was a retrospective analysis of 100 cases of BCCs reported in the Department of Pathology over a 9-year period from 2006 to 2014. Results The mean age of presentation was 62 years. There was slight female preponderance (56%). The most common location was face (65%) and the most common presentation was ulceration (45%). Of the 100 BCCs, 50% were nodular, 13% infiltrating, 6% basosquamous, 4% superficial, 3% keratotic, 3% multinodular and 1% mixed. Conclusion BCC, besides being the commonest cutaneous cancer, is also known for its numerous histological patterns which are shown to have prognostic implications. This study reveals the frequency of the various histological patterns of BCC in southern Karnataka, where it has been rarely studied before. PMID:27504291

  17. Basal Lamina Mimetic Nanofibrous Peptide Networks for Skeletal Myogenesis

    NASA Astrophysics Data System (ADS)

    Yasa, I. Ceren; Gunduz, Nuray; Kilinc, Murat; Guler, Mustafa O.; Tekinay, Ayse B.

    2015-11-01

    Extracellular matrix (ECM) is crucial for the coordination and regulation of cell adhesion, recruitment, differentiation and death. Therefore, equilibrium between cell-cell and cell-matrix interactions and matrix-associated signals are important for the normal functioning of cells, as well as for regeneration. In this work, we describe importance of adhesive signals for myoblast cells’ growth and differentiation by generating a novel ECM mimetic peptide nanofiber scaffold system. We show that not only structure but also composition of bioactive signals are important for cell adhesion, growth and differentiation by mimicking the compositional and structural properties of native skeletal muscle basal lamina. We conjugated laminin-derived integrin binding peptide sequence, “IKVAV”, and fibronectin-derived well known adhesive sequence, “RGD”, into peptide nanostructures to provide adhesive and myogenic cues on a nanofibrous morphology. The myogenic and adhesive signals exhibited a synergistic effect on model myoblasts, C2C12 cells. Our results showed that self-assembled peptide nanofibers presenting laminin derived epitopes support adhesion, growth and proliferation of the cells and significantly promote the expression of skeletal muscle-specific marker genes. The functional peptide nanofibers used in this study present a biocompatible and biodegradable microenvironment, which is capable of supporting the growth and differentiation of C2C12 myoblasts into myotubes.

  18. Basal Lamina Mimetic Nanofibrous Peptide Networks for Skeletal Myogenesis

    PubMed Central

    Yasa, I. Ceren; Gunduz, Nuray; Kilinc, Murat; Guler, Mustafa O.; Tekinay, Ayse B.

    2015-01-01

    Extracellular matrix (ECM) is crucial for the coordination and regulation of cell adhesion, recruitment, differentiation and death. Therefore, equilibrium between cell-cell and cell-matrix interactions and matrix-associated signals are important for the normal functioning of cells, as well as for regeneration. In this work, we describe importance of adhesive signals for myoblast cells’ growth and differentiation by generating a novel ECM mimetic peptide nanofiber scaffold system. We show that not only structure but also composition of bioactive signals are important for cell adhesion, growth and differentiation by mimicking the compositional and structural properties of native skeletal muscle basal lamina. We conjugated laminin-derived integrin binding peptide sequence, “IKVAV”, and fibronectin-derived well known adhesive sequence, “RGD”, into peptide nanostructures to provide adhesive and myogenic cues on a nanofibrous morphology. The myogenic and adhesive signals exhibited a synergistic effect on model myoblasts, C2C12 cells. Our results showed that self-assembled peptide nanofibers presenting laminin derived epitopes support adhesion, growth and proliferation of the cells and significantly promote the expression of skeletal muscle-specific marker genes. The functional peptide nanofibers used in this study present a biocompatible and biodegradable microenvironment, which is capable of supporting the growth and differentiation of C2C12 myoblasts into myotubes. PMID:26555958

  19. Basal glucosuria is ubiquitous in critically ill patients.

    PubMed

    Brunner, Richard; Kurz, Annabella; Adelsmayr, Gabriel; Holzinger, Ulrike

    2015-04-01

    The 'renal threshold for glucose' has never been evaluated in critically ill patients. Therefore, we aimed to investigate the renal glucose threshold in this patient group using high-sensitivity urine glucose assays. In this retrospective analysis of prospectively collected data, we analysed 100 consecutive critically ill patients from a medical intensive care unit (ICU). Arterial blood glucose and spot urine glucose were simultaneously quantified daily during the first week after ICU admission. Three hundred seventy-three pairs of blood/urine glucose were plotted in five pre-defined categories of blood glucose (<80, 80-109, 110-139, 140-179 and ≥180 mg/dL). Urine glucose values of the five categories were compared using the Kruskal-Wallis test to assess the relation with blood glucose. Urine glucose was detected in virtually all of the urine samples. Urine glucose showed a positive nonlinear correlation with blood glucose and was significantly elevated at blood glucose levels of 140-179 and ≥180 mg/dL compared with lower blood glucose ranges. Basal glucosuria is ubiquitous in critically ill patients. A 'soft' renal threshold for glucose is present at blood glucose levels in the range of 140-179 mg/dL. PMID:25810226

  20. What do the basal ganglia do? A modeling perspective.

    PubMed

    Chakravarthy, V S; Joseph, Denny; Bapi, Raju S

    2010-09-01

    Basal ganglia (BG) constitute a network of seven deep brain nuclei involved in a variety of crucial brain functions including: action selection, action gating, reward based learning, motor preparation, timing, etc. In spite of the immense amount of data available today, researchers continue to wonder how a single deep brain circuit performs such a bewildering range of functions. Computational models of BG have focused on individual functions and fail to give an integrative picture of BG function. A major breakthrough in our understanding of BG function is perhaps the insight that activities of mesencephalic dopaminergic cells represent some form of 'reward' to the organism. This insight enabled application of tools from 'reinforcement learning,' a branch of machine learning, in the study of BG function. Nevertheless, in spite of these bright spots, we are far from the goal of arriving at a comprehensive understanding of these 'mysterious nuclei.' A comprehensive knowledge of BG function has the potential to radically alter treatment and management of a variety of BG-related neurological disorders (Parkinson's disease, Huntington's chorea, etc.) and neuropsychiatric disorders (schizophrenia, obsessive compulsive disorder, etc.) also. In this article, we review the existing modeling literature on BG and hypothesize an integrative picture of the function of these nuclei. PMID:20644953

  1. Endoscopic surgery for congenital basal meningoencephaloceles in children.

    PubMed

    Wu, Xuewen; Zhang, Junyi; Zhang, Hua; Xie, Zhihai; Fan, Ruohao; Liu, Yong; Wu, Bei; Sun, Hong; Jiang, Weihong

    2016-06-01

    Conclusions Endoscopic surgery is safe and effective for children with congenital basal meningoencephaloceles (CBMs); it provides an acceptable operative outcome with a short recovery time and fewer complications and may be considered as a primary approach. Objectives To explore the safety and effectiveness of using transnasal or transoral endoscopic surgery on children with CBMs. Methods The clinical data of eight CBMs children who underwent transnasal or transoral endoscopic surgery in a hospital from January 2011 to January 2015 were collected. The presenting symptoms, lesion locations, surgical outcomes, and complications were examined retrospectively. Results Of the eight children, five (62.5%) patients were male, and their ages ranged from 1 year and 6 months to 14 years (median of 9 years). Six patients presented with the transethmoidal sub-type, and two presented with the transsphenoidal sub-type. The average hospital stay of all patients was 8.6 ± 2.6 days. There were neither intra-operative nor post-operative complications observed in any of the cases during the follow-ups that occurred between 6-54 months (mean of 15.5 months). PMID:26848970

  2. Observation of sonified movements engages a basal ganglia frontocortical network

    PubMed Central

    2013-01-01

    Background Producing sounds by a musical instrument can lead to audiomotor coupling, i.e. the joint activation of the auditory and motor system, even when only one modality is probed. The sonification of otherwise mute movements by sounds based on kinematic parameters of the movement has been shown to improve motor performance and perception of movements. Results Here we demonstrate in a group of healthy young non-athletes that congruently (sounds match visual movement kinematics) vs. incongruently (no match) sonified breaststroke movements of a human avatar lead to better perceptual judgement of small differences in movement velocity. Moreover, functional magnetic resonance imaging revealed enhanced activity in superior and medial posterior temporal regions including the superior temporal sulcus, known as an important multisensory integration site, as well as the insula bilaterally and the precentral gyrus on the right side. Functional connectivity analysis revealed pronounced connectivity of the STS with the basal ganglia and thalamus as well as frontal motor regions for the congruent stimuli. This was not seen to the same extent for the incongruent stimuli. Conclusions We conclude that sonification of movements amplifies the activity of the human action observation system including subcortical structures of the motor loop. Sonification may thus be an important method to enhance training and therapy effects in sports science and neurological rehabilitation. PMID:23496827

  3. Chemopreventive opportunities to control basal cell carcinoma: Current perspectives.

    PubMed

    Tilley, Cynthia; Deep, Gagan; Agarwal, Rajesh

    2015-09-01

    Basal cell carcinoma (BCC) is a major health problem with approximately 2.8 million new cases diagnosed each year in the United States. BCC incidences have continued to rise due to lack of effective chemopreventive options. One of the key molecular characteristics of BCC is the sustained activation of hedgehog signaling through inactivating mutations in the tumor suppressor gene patch (Ptch) or activating mutations in Smoothened. In the past, several studies have addressed targeting the activated hedgehog pathway for the treatment and prevention of BCC, although with toxic effects. Other studies have attempted BCC chemoprevention through targeting the promotional phase of the disease especially the inflammatory component. The compounds that have been utilized in pre-clinical and/or clinical studies include green and black tea, difluoromethylornithine, thymidine dinucleotide, retinoids, non-steroidal anti-inflammatory drugs, vitamin D3, and silibinin. In this review, we have discussed genetic and epigenetic modifications that occur during BCC development as well as the current state of BCC pre-clinical and clinical chemoprevention studies. PMID:26053157

  4. Diagnosis and Management of Hereditary Basal Cell Skin Cancer.

    PubMed

    Shanley, Susan; McCormack, Christopher

    2016-01-01

    Basal cell carcinoma (BCC) is the most common cancer in Caucasians worldwide and its incidence is rising. It is generally considered a sporadic tumour, most likely to affect fair-skinned individuals exposed to ultraviolet (UV) radiation. This chapter focusses on the approach to recognising the relatively few individuals in whom a high-risk hereditary susceptibility may be present. Gorlin syndrome is the main consideration and the gene most commonly mutated is PTCH1, a key regulator of the Hedgehog developmental pathway. Recently, loss of function of another gene in the same pathway, SUFU, has been found to explain a subset of families. Understanding the pathogenesis of familial BCCs has advanced the understanding of the biology of sporadic tumours and led to targeted therapy trials. The management of familial BCCs remains a challenge due to significant unmet needs for non-surgical treatments and a high burden of disease for the individual. Together with the prospect of advances in gene discovery and translation, these challenges highlight the need for ongoing review of at-risk and affected individuals by a multidisciplinary team. PMID:27075355

  5. Basal ganglia cholinergic and dopaminergic function in progressive supranuclear palsy.

    PubMed

    Warren, Naomi M; Piggott, Margaret A; Greally, Elizabeth; Lake, Michelle; Lees, Andrew J; Burn, David J

    2007-08-15

    Progressive Supranuclear Palsy (PSP) is a progressive neurodegenerative disorder. In contrast to Parkinson's disease (PD) and dementia with Lewy bodies (DLB), replacement therapy with dopaminergic and cholinergic agents in PSP has been disappointing. The neurochemical basis for this is unclear. Our objective was to measure dopaminergic and cholinergic receptors in the basal ganglia of PSP and control brains. We measured, autoradiographically, dopaminergic (dopamine transporter, 125I PE2I and dopamine D2 receptors, 125I epidepride) and cholinergic (nicotinic alpha4beta2 receptors, 125I 5IA85380 and muscarinic M1 receptors, 3H pirenzepine) parameters in the striatum and pallidum of pathologically confirmed PSP cases (n=15) and controls (n=32). In PSP, there was a marked loss of dopamine transporter and nicotinic alpha4beta2 binding in the striatum and pallidum, consistent with loss of nigrostriatal neurones. Striatal D2 receptors were increased in the caudate and muscarinic M1 receptors were unchanged compared with controls. These results do not account for the poor response to dopaminergic and cholinergic replacement therapies in PSP, and suggest relative preservation of postsynaptic striatal projection neurones bearing D2/M1 receptors. PMID:17534953

  6. Neuropsychological impairment after hemorrhagic stroke in basal ganglia.

    PubMed

    Su, Chwen-Yng; Chen, Hui-Mei; Kwan, Aij-Lie; Lin, Yueh-Hsieh; Guo, Nai-Wen

    2007-05-01

    We aimed to determine the severity and pattern of cognitive dysfunction in patients with basal ganglia (BG) hemorrhage within the first 6 months after stroke and to identify its clinical correlates. The study samples consisted of 30 patients with BG hemorrhage and 37 healthy controls. A comprehensive neuropsychological battery including tests of attention, memory, language, visuospatial function, and executive function was administered to all participants. Relative to healthy controls, BG patients performed significantly worse across different cognitive domains after controlling for age, sex, and education. 96.7% of patients displayed defective performance on at least three neuropsychological tests. Discriminant function analysis showed that visuospatial function and memory were the best predictors of group membership (patient/control), with an overall classification rate of 95.5%. Only side of stroke and admission Glasgow Coma Scale (GCS) score correlated significantly with some of the cognitive domains. The widespread pattern of cognitive deficits seen in BG patients provides evidence for the substantial involvement of the BG in many neuronal pathways connecting cortical and subcortical brain areas responsible for various cognitive functions. PMID:17336034

  7. Origins of basal ganglia output signals in singing juvenile birds.

    PubMed

    Pidoux, Morgane; Bollu, Tejapratap; Riccelli, Tori; Goldberg, Jesse H

    2015-02-01

    Across species, complex circuits inside the basal ganglia (BG) converge on pallidal output neurons that exhibit movement-locked firing patterns. Yet the origins of these firing patterns remain poorly understood. In songbirds during vocal babbling, BG output neurons homologous to those found in the primate internal pallidal segment are uniformly activated in the tens of milliseconds prior to syllable onsets. To test the origins of this remarkably homogenous BG output signal, we recorded from diverse upstream BG cell types during babbling. Prior to syllable onsets, at the same time that internal pallidal segment-like neurons were activated, putative medium spiny neurons, fast spiking and tonically active interneurons also exhibited transient rate increases. In contrast, pallidal neurons homologous to those found in primate external pallidal segment exhibited transient rate decreases. To test origins of these signals, we performed recordings following lesion of corticostriatal inputs from premotor nucleus HVC. HVC lesions largely abolished these syllable-locked signals. Altogether, these findings indicate a striking homogeneity of syllable timing signals in the songbird BG during babbling and are consistent with a role for the indirect and hyperdirect pathways in transforming cortical inputs into BG outputs during an exploratory behavior. PMID:25392171

  8. Basal entrainment by Newtonian gravity-driven flows

    NASA Astrophysics Data System (ADS)

    Bates, Belinda M.; Andreini, Nicolas; Ancey, Christophe

    2016-05-01

    Gravity-driven flows can erode the bed along which they descend and increase their mass by a factor of 10 or more. This process is called "basal entrainment." Although documented by field observations and laboratory experiments, it remains poorly understood. This paper examines what happens when a viscous gravity-driven flow generated by releasing a fixed volume of incompressible Newtonian fluid encounters a stationary layer (composed of fluid with the same density and viscosity). Models based on depth-averaged mass and momentum balance equations deal with bed-flow interfaces as shock waves. In contrast, we use an approach involving the long-wave approximation of the Navier-Stokes equations (lubrication theory), and in this context, bed-flow interfaces are acceleration waves that move quickly across thin stationary layers. The incoming flow digs down into the bed, pushing up downstream material, thus advancing the flow front. Extending the method used by Huppert ["The propagation of two-dimensional and axisymmetric viscous gravity currents over a rigid horizontal surface," J. Fluid Mech. 121, 43-58 (1982)] for modeling viscous dam-break waves, we end up with a nonlinear diffusion equation for the flow depth, which is solved numerically. Theory is compared with experimental results. Excellent agreement is found in the limit of low Reynolds numbers (i.e., for flow Reynolds numbers lower than 20) for the front position over time and flow depth profile.

  9. Ionizing Radiation Exposure and Basal Cell Carcinoma Pathogenesis.

    PubMed

    Li, Changzhao; Athar, Mohammad

    2016-03-01

    This commentary summarizes studies showing risk of basal cell carcinoma (BCC) development in relationship to environmental, occupational and therapeutic exposure to ionizing radiation (IR). BCC, the most common type of human cancer, is driven by the aberrant activation of hedgehog (Hh) signaling. Ptch, a tumor suppressor gene of Hh signaling pathway, and Smoothened play a key role in the development of radiation-induced BCCs in animal models. Epidemiological studies provide evidence that humans exposed to radiation as observed among the long-term, large scale cohorts of atomic bomb survivors, bone marrow transplant recipients, patients with tinea capitis and radiologic workers enhances risk of BCCs. Overall, this risk is higher in Caucasians than other races. People who were exposed early in life develop more BCCs. The enhanced IR correlation with BCC and not other common cutaneous malignancies is intriguing. The mechanism underlying these observations remains undefined. Understanding interactions between radiation-induced signaling pathways and those which drive BCC development may be important in unraveling the mechanism associated with this enhanced risk. Recent studies showed that Vismodegib, a Smoothened inhibitor, is effective in treating radiation-induced BCCs in humans, suggesting that common strategies are required for the intervention of BCCs development irrespective of their etiology. PMID:26930381

  10. Arginine kinase from Myzostoma cirriferum, a basal member of annelids.

    PubMed

    Yano, Daichi; Mimura, Sayo; Uda, Kouji; Suzuki, Tomohiko

    2016-08-01

    We assembled a phosphagen kinase gene from the Expressed Sequence Tags database of Myzostoma cirriferum, a basal member of annelids. The assembled gene sequence was synthesized using an overlap extension polymerase chain reaction method and was expressed in Escherichia coli. The recombinant enzyme (355 residues) exhibited monomeric behavior on a gel filtration column and showed strong activity only for l-arginine. Thus, the enzyme was identified as arginine kinase (AK). The two-substrate kinetic parameters were obtained and compared with other AKs. Phylogenetic analysis of amino acid sequences of phosphagen kinases indicated that the Myzostoma AK gene lineage differed from that of the polychaete Sabellastarte spectabilis AK, which is a dimer of creatine kinase (CK) origin. It is likely that the Myzostoma AK gene lineage was lost at an early stage of annelid evolution and that Sabellastarte AK evolved secondarily from the CK gene. This work contributes to our understanding of the evolution of phosphagen kinases of annelids with marked diversity. PMID:27095694

  11. Basal ganglia outputs map instantaneous position coordinates during behavior.

    PubMed

    Barter, Joseph W; Li, Suellen; Sukharnikova, Tatyana; Rossi, Mark A; Bartholomew, Ryan A; Yin, Henry H

    2015-02-11

    The basal ganglia (BG) are implicated in many movement disorders, yet how they contribute to movement remains unclear. Using wireless in vivo recording, we measured BG output from the substantia nigra pars reticulata (SNr) in mice while monitoring their movements with video tracking. The firing rate of most nigral neurons reflected Cartesian coordinates (either x- or y-coordinates) of the animal's head position during movement. The firing rates of SNr neurons are either positively or negatively correlated with the coordinates. Using an egocentric reference frame, four types of neurons can be classified: each type increases firing during movement in a particular direction (left, right, up, down), and decreases firing during movement in the opposite direction. Given the high correlation between the firing rate and the x and y components of the position vector, the movement trajectory can be reconstructed from neural activity. Our results therefore demonstrate a quantitative and continuous relationship between BG output and behavior. Thus, a steady BG output signal from the SNr (i.e., constant firing rate) is associated with the lack of overt movement, when a stable posture is maintained by structures downstream of the BG. Any change in SNr firing rate is associated with a change in position (i.e., movement). We hypothesize that the SNr output quantitatively determines the direction, velocity, and amplitude of voluntary movements. By changing the reference signals to downstream position control systems, the BG can produce transitions in body configurations and initiate actions. PMID:25673860

  12. Basal Ganglia Outputs Map Instantaneous Position Coordinates during Behavior

    PubMed Central

    Barter, Joseph W.; Li, Suellen; Sukharnikova, Tatyana; Rossi, Mark A.; Bartholomew, Ryan A.

    2015-01-01

    The basal ganglia (BG) are implicated in many movement disorders, yet how they contribute to movement remains unclear. Using wireless in vivo recording, we measured BG output from the substantia nigra pars reticulata (SNr) in mice while monitoring their movements with video tracking. The firing rate of most nigral neurons reflected Cartesian coordinates (either x- or y-coordinates) of the animal's head position during movement. The firing rates of SNr neurons are either positively or negatively correlated with the coordinates. Using an egocentric reference frame, four types of neurons can be classified: each type increases firing during movement in a particular direction (left, right, up, down), and decreases firing during movement in the opposite direction. Given the high correlation between the firing rate and the x and y components of the position vector, the movement trajectory can be reconstructed from neural activity. Our results therefore demonstrate a quantitative and continuous relationship between BG output and behavior. Thus, a steady BG output signal from the SNr (i.e., constant firing rate) is associated with the lack of overt movement, when a stable posture is maintained by structures downstream of the BG. Any change in SNr firing rate is associated with a change in position (i.e., movement). We hypothesize that the SNr output quantitatively determines the direction, velocity, and amplitude of voluntary movements. By changing the reference signals to downstream position control systems, the BG can produce transitions in body configurations and initiate actions. PMID:25673860

  13. New common variants affecting susceptibility to basal cell carcinoma.

    PubMed

    Stacey, Simon N; Sulem, Patrick; Masson, Gisli; Gudjonsson, Sigurjon A; Thorleifsson, Gudmar; Jakobsdottir, Margret; Sigurdsson, Asgeir; Gudbjartsson, Daniel F; Sigurgeirsson, Bardur; Benediktsdottir, Kristrun R; Thorisdottir, Kristin; Ragnarsson, Rafn; Scherer, Dominique; Hemminki, Kari; Rudnai, Peter; Gurzau, Eugene; Koppova, Kvetoslava; Botella-Estrada, Rafael; Soriano, Virtudes; Juberias, Pablo; Saez, Berta; Gilaberte, Yolanda; Fuentelsaz, Victoria; Corredera, Cristina; Grasa, Matilde; Höiom, Veronica; Lindblom, Annika; Bonenkamp, Johannes J; van Rossum, Michelle M; Aben, Katja K H; de Vries, Esther; Santinami, Mario; Di Mauro, Maria G; Maurichi, Andrea; Wendt, Judith; Hochleitner, Pia; Pehamberger, Hubert; Gudmundsson, Julius; Magnusdottir, Droplaug N; Gretarsdottir, Solveig; Holm, Hilma; Steinthorsdottir, Valgerdur; Frigge, Michael L; Blondal, Thorarinn; Saemundsdottir, Jona; Bjarnason, Hjördis; Kristjansson, Kristleifur; Bjornsdottir, Gyda; Okamoto, Ichiro; Rivoltini, Licia; Rodolfo, Monica; Kiemeney, Lambertus A; Hansson, Johan; Nagore, Eduardo; Mayordomo, José I; Kumar, Rajiv; Karagas, Margaret R; Nelson, Heather H; Gulcher, Jeffrey R; Rafnar, Thorunn; Thorsteinsdottir, Unnur; Olafsson, Jon H; Kong, Augustine; Stefansson, Kari

    2009-08-01

    In a follow-up to our previously reported genome-wide association study of cutaneous basal cell carcinoma (BCC), we describe here several new susceptibility variants. SNP rs11170164, encoding a G138E substitution in the keratin 5 (KRT5) gene, affects risk of BCC (OR = 1.35, P = 2.1 x 10(-9)). A variant at 9p21 near CDKN2A and CDKN2B also confers susceptibility to BCC (rs2151280[C]; OR = 1.19, P = 6.9 x 10(-9)), as does rs157935[T] at 7q32 near the imprinted gene KLF14 (OR = 1.23, P = 5.7 x 10(-10)). The effect of rs157935[T] is dependent on the parental origin of the risk allele. None of these variants were found to be associated with melanoma or fair-pigmentation traits. A melanoma- and pigmentation-associated variant in the SLC45A2 gene, L374F, is associated with risk of both BCC and squamous cell carcinoma. Finally, we report conclusive evidence that rs401681[C] in the TERT-CLPTM1L locus confers susceptibility to BCC but protects against melanoma. PMID:19578363

  14. Clinicopathological analysis of recurrent basal cell carcinoma of the eyelid

    PubMed Central

    Zieliński, Tomasz; Antoszewski, Bogusław; Sporny, Stanisław

    2016-01-01

    Introduction Basal cell carcinoma (BCC) is the most common malignant neoplasm of the eyelids and surrounding structures, usually developing in the area of the lower lid and medial canthus. Invasive forms of BCC are connected with a high risk of recurrence, often due to incomplete excision of these lesions. Aim Clinical and pathological analysis of recurrent BCCs of the eyelids and surrounding structures. Material and methods We present clinical and pathological analysis including immunohistochemical reaction to Ki-67 antigen of 19 patients (11 women, 8 men) operated for recurrent BCCs of the eyelids in 2000–2012. Results In most cases, recurrences were present on the lower lid and in the medial canthus. In 15 patients the histopathological type did not change and in 4 cases it transformed into more invasive forms. The values of Ki-67 index for primary BCCs ranged between 1% and 20%, and for relapsing lesions between 11% and 48%. Conclusions Proper clinical and pathological evaluation to determine the risk of relapse in BCCs of the eyelids and surrounding structures should include the analysis of prognostic factors, in particular location and size, histopathological type and radicalness of surgical treatment of primary BCCs. Clinical and pathological analysis of patients with recurrent BCC of the eyelids and surrounding structures should be combined with the evaluation of proliferation index Ki-67, which is essential for prognosis and choice of the appropriate therapeutic method. PMID:26985178

  15. Sonidegib phosphate: new approval for basal cell carcinoma.

    PubMed

    Tibes, R

    2016-05-01

    Basal cell carcinoma (BCC), although mostly locally confined, is the most common cancer. Most BCCs harbor inactivating mutations in the membrane receptor/gene Ptch, thereby activating the Hedgehog signaling pathway (Hh) via the essential signaling molecule Smoothened (SMO). Novel small-molecule inhibitors or antagonists of SMO have shown excellent response rates in patients with locally advanced, unresectable and metastatic BCC in roughly 35-60% of patients, with disease control rates and clinical benefit being even higher. Sonidegib is the second-in-class SMO inhibitor approved for locally advanced, unresectable and metastatic BCC. Sonidegib is given once daily continuously, with specific side effects as listed in the label indication. Resistance develops over time and knowledge gleaned from other SMO inhibitors indicates that SMO mutations preventing drug binding as well as mechanisms activating the Hh pathway downstream of SMO are responsible, ultimately reactivating Hh pathway signaling. The next challenge will be to define novel salvage and SMO combination strategies for BCC and other tumors. PMID:27376162

  16. Comparisons of Young Children's Syntax to the Syntax of Their Basal Readers.

    ERIC Educational Resources Information Center

    Lehnert, Linda; Johnson, Barbara

    1984-01-01

    Reveals that in the average number of words per T-unit, the complexity of basal reader passages generally exceeds that of children's oral language, and that none of the basal series studied exhibited a graduated increase in average number of words per T-unit among passages in the same reader. (FL)

  17. Dick and Jane Are Dead: Basal Reader Takes a Back Seat to Student Writings.

    ERIC Educational Resources Information Center

    Oxendine, Linda

    A second grade teacher in a rural Appalachian school draws heavily on familiar regional literature and the children's own rich mountain heritage and culture to teach reading to her students, covering the required basal readings in only one day per week. Students use the basals on Mondays and retell the texts on paper. They spend the rest of the…

  18. Intraparenchymal meningioma within the basal ganglia of a child: A case report.

    PubMed

    Reynolds, Matthew R; Boland, Michael R; Arias, Eric J; Farrell, Michael; Javadpour, Mohsen; Caird, John

    2016-06-01

    Intraparenchymal meningiomas are rare. To date, no such lesion has been reported within the basal ganglia of a paediatric patient. Here, we describe the case of a 15-year-old-boy who presented with symptoms referable to a cystic, calcified, left basal ganglia intraparenchymal meningioma and discuss the surgical management of this lesion. PMID:26466020

  19. An Analysis of Reading Questions in Basal Reading Series Based on Bloom's Taxonomy.

    ERIC Educational Resources Information Center

    Habecker, James Edward

    A scheme based on Bloom's taxonomy of educational objectives was developed for classifying questions asked in basal reading manuals. A total of 6,988 questions from 144 lesson plans selected from basal readers from four major publishers were analyzed; 2,754 questions were from the 1950-1959 time period, and 4,234 were from the 1966-1975 time…

  20. A New Look at the Journey from Basal to Whole Language.

    ERIC Educational Resources Information Center

    Thelen, Judith N.

    1995-01-01

    Reexamines the pros and cons of traditional basal reader and literature-based reading programs and those based on the whole language approach. Compares and contrasts classroom teaching methods, goals, and some outcomes. Includes Venn diagram showing overlap and divergence of whole language, literature-based, and traditional basal methods. (ET)

  1. Do Current Basal Series Use Clear Explanations and Correct Exemplars in Teaching Prefixes?

    ERIC Educational Resources Information Center

    Volpe, Myra Elaine

    A study (replicating a similar 1977 study by S. Stotsky), examined whether current basal series teach prefixion clearly. Teacher's guides, student texts, and workbooks of nine popular basal reader series were examined to ascertain whether they offered a clear definition of the term "prefix" and whether that definition was reinforced by the use of…

  2. Phenotypes of the ovarian follicular basal lamina predict developmental competence of oocytes

    PubMed Central

    Irving-Rodgers, Helen F.; Morris, Stephanie; Collett, Rachael A.; Peura, Teija T.; Davy, Margaret; Thompson, Jeremy G.; Mason, Helen D.; Rodgers, Raymond J.

    2009-01-01

    BACKGROUND The ovarian follicular basal lamina underlies the epithelial membrana granulosa and maintains the avascular intra-follicular compartment. Additional layers of basal lamina occur in a number of pathologies, including pili annulati and diabetes. We previously found additional layers of follicular basal lamina in a significant percentage of healthy bovine follicles. We wished to determine if this phenomenon existed in humans, and if it was related to oocyte function in the bovine. METHODS AND RESULTS We examined follicles from human ovaries (n = 18) by electron microscopy and found that many follicles had additional layers of basal lamina. Oocytes (n = 222) from bovine follicles with normal or unusual basal laminas were isolated and their ability to undergo in vitro maturation, fertilization and culture to blastocyst was compared. Healthy bovine follicles with a single layer of basal lamina had oocytes with significantly (P < 0.01) greater developmental competence than healthy follicles with additional layers of follicular basal lamina (65% versus 28%). CONCLUSIONS These findings provide direct evidence that the phenotype of the follicular basal lamina is related to oocyte competence. PMID:19095662

  3. The Relevance of Illustration in Basal Readers as It Relates to Contextual Meaning.

    ERIC Educational Resources Information Center

    Chesnov, Wendy Beth

    A study examined the hypothesis that illustrations found in first-grade basal texts do not always relate to context. Six texts were analyzed to determine the percentage of illustration miscues appearing in each story. The basal readers used were: "Story Clouds," Scott Foresman Reading: An American Tradition (1987); "Red Rock," Rand McNally Reading…

  4. The effect of basal channels on oceanic ice-shelf melting

    NASA Astrophysics Data System (ADS)

    Millgate, Thomas; Holland, Paul R.; Jenkins, Adrian; Johnson, Helen L.

    2013-12-01

    The presence of ice-shelf basal channels has been noted in a number of Antarctic and Greenland ice shelves, but their impact on basal melting is not fully understood. Here we use the Massachusetts Institute of Technology general circulation model to investigate the effect of ice-shelf basal channels on oceanic melt rate for an idealized ice shelf resembling the floating tongue of Petermann Glacier in Greenland. The introduction of basal channels prevents the formation of a single geostrophically balanced boundary current; instead the flow is diverted up the right-hand (Coriolis-favored) side of each channel, with a return flow in the opposite direction on the left-hand side. As the prescribed number of basal channels is increased the mean basal melt rate decreases, in agreement with previous studies. For a small number of relatively wide channels the subice flow is found to be a largely geostrophic horizontal circulation. The reduction in melt rate is then caused by an increase in the relative contribution of weakly melting channel crests and keels. For a larger number of relatively narrow channels, the subice flow changes to a vertical overturning circulation. This change in circulation results in a weaker sensitivity of melt rates to channel size. The transition between the two regimes is governed by the Rossby radius of deformation. Our results explain why basal channels play an important role in regulating basal melting, increasing the stability of ice shelves.

  5. Distinct Hippocampal and Basal Ganglia Contributions to Probabilistic Learning and Reversal

    ERIC Educational Resources Information Center

    Shohamy, Daphna; Myers, Catherine E.; Hopkins, Ramona O.; Sage, Jake; Gluck, Mark A.

    2009-01-01

    The hippocampus and the basal ganglia are thought to play fundamental and distinct roles in learning and memory, supporting two dissociable memory systems. Interestingly, however, the hippocampus and the basal ganglia have each, separately, been implicated as necessary for reversal learning--the ability to adaptively change a response when…

  6. ON POSSIBLE VARIATIONS OF BASAL Ca II K CHROMOSPHERIC LINE PROFILES WITH THE SOLAR CYCLE

    SciTech Connect

    Pevtsov, Alexei A.; Uitenbroek, Han; Bertello, Luca E-mail: huitenbroek@nso.edu

    2013-04-10

    We use daily observations of the Ca II K line profiles of the Sun-as-a-star taken with the Integrated Sunlight Spectrometer from 2006 December through 2011 July to deconvolve the contributions from the quiet (basal) chromosphere and with magnetic network/plage areas. The 0.5 A emission index computed from basal profiles shows a significantly reduced modulation (as compared with one derived from the observed profiles) corresponding to the Sun's rotation. For basal contribution of the Ca II K line, the peak in power spectrum corresponding to solar rotation is broad and not well defined. Power spectra for the plage contribution show two narrow well-defined peaks corresponding to solar rotation at two distinct latitudes, in agreement with the latitudinal distribution of activity on the Sun at the end of Cycle 23 and beginning of Cycle 24. We use the lack of a signature of solar rotation in the basal (quiet Sun) component as an indication of a successful removal of the active Sun (plage) component. Even though the contribution from solar activity is removed from the basal line profiles, we find a weak dependency of intensity in the line core (K3) of basal profiles with the phase of the solar cycle. Such dependency could be the result of changes in thermal properties of basal chromosphere with the solar cycle. As an alternative explanation, we also discuss a possibility that the basal component does not change with the phase of the solar cycle.

  7. Treatment of Basal Cell Carcinoma with Curettage Followed by Imiquimod 3.75% Cream

    PubMed Central

    Patel, Rita V.; Birge, Miriam B.

    2011-01-01

    Basal cell carcinoma is the most common form of nonmelanoma skin cancer in the United States. Treatment modalities include both surgical, medical, or combination therapy. In the following case, the authors report the successful treatment of a basal cell carcinoma on the nose with curettage followed by topical imiquimod 3.75% cream. PMID:21607193

  8. Stem cell and neurogenic gene-expression profiles link prostate basal cells to aggressive prostate cancer

    PubMed Central

    Zhang, Dingxiao; Park, Daechan; Zhong, Yi; Lu, Yue; Rycaj, Kiera; Gong, Shuai; Chen, Xin; Liu, Xin; Chao, Hsueh-Ping; Whitney, Pamela; Calhoun-Davis, Tammy; Takata, Yoko; Shen, Jianjun; Iyer, Vishwanath R.; Tang, Dean G.

    2016-01-01

    The prostate gland mainly contains basal and luminal cells constructed as a pseudostratified epithelium. Annotation of prostate epithelial transcriptomes provides a foundation for discoveries that can impact disease understanding and treatment. Here we describe a genome-wide transcriptome analysis of human benign prostatic basal and luminal epithelial populations using deep RNA sequencing. Through molecular and biological characterizations, we show that the differential gene-expression profiles account for their distinct functional properties. Strikingly, basal cells preferentially express gene categories associated with stem cells, neurogenesis and ribosomal RNA (rRNA) biogenesis. Consistent with this profile, basal cells functionally exhibit intrinsic stem-like and neurogenic properties with enhanced rRNA transcription activity. Of clinical relevance, the basal cell gene-expression profile is enriched in advanced, anaplastic, castration-resistant and metastatic prostate cancers. Therefore, we link the cell-type-specific gene signatures to aggressive subtypes of prostate cancer and identify gene signatures associated with adverse clinical features. PMID:26924072

  9. Towards a Biopsychological Understanding of Costly Punishment: The Role of Basal Cortisol

    PubMed Central

    Pfattheicher, Stefan; Keller, Johannes

    2014-01-01

    Recent findings have documented a negative relation of basal endogenous cortisol and aggression after a provocation (i.e., reactive aggression) in humans. We build on these findings and investigated the relation of endogenous cortisol and reactive aggression in a social dilemma situation, that is, costly punishment of individuals who did not appropriately contribute to a common group project. Specifically, we predicted that basal cortisol is negatively related to costly punishment of uncooperative individuals. In the present study, basal cortisol was assessed prior to a public goods game with the option to punish other group members. In line with previous research on reactive aggression and basal cortisol, we found that basal cortisol was indeed negatively related to costly punishment. The findings are important for understanding costly punishment because this tendency has been documented as a possible basis for the evolution of cooperation. PMID:24416441

  10. Cell cycle-dependent regulation of RNA polymerase II basal transcription activity.

    PubMed Central

    Yonaha, M; Chibazakura, T; Kitajima, S; Yasukochi, Y

    1995-01-01

    Regulation of transcription by RNA polymerase II (pol II) in eukaryotic cells requires both basal and regulatory transcription factors. In this report we have investigated in vitro pol II basal transcription activity during the cell cycle by using nuclear extracts from synchronized HeLa cells. It is shown that pol II basal transcription activity is low in the S and G2 phases and high in early G1 phase and TFIID is the rate limiting component of pol II basal transcription activity during the cell cycle. Further analyses reveal that TFIID exists as a less active form in the S and G2 phases and nuclear extracts from S and G2 phase cells contain a heat-sensitive repressor(s) of TATA box binding protein (TBP). These results suggest that pol II basal transcription activity is regulated by a qualitative change in the TFIID complex, which could involve repression of TBP, during the cell cycle. Images PMID:7479063

  11. Injury induces direct lineage segregation of functionally distinct airway basal stem/progenitor cell subpopulations.

    PubMed

    Pardo-Saganta, Ana; Law, Brandon M; Tata, Purushothama Rao; Villoria, Jorge; Saez, Borja; Mou, Hongmei; Zhao, Rui; Rajagopal, Jayaraj

    2015-02-01

    Following injury, stem cells restore normal tissue architecture by producing the proper number and proportions of differentiated cells. Current models of airway epithelial regeneration propose that distinct cytokeratin 8-expressing progenitor cells, arising from p63(+) basal stem cells, subsequently differentiate into secretory and ciliated cell lineages. We now show that immediately following injury, discrete subpopulations of p63(+) airway basal stem/progenitor cells themselves express Notch pathway components associated with either secretory or ciliated cell fate commitment. One basal cell population displays intracellular Notch2 activation and directly generates secretory cells; the other expresses c-myb and directly yields ciliated cells. Furthermore, disrupting Notch ligand activity within the basal cell population at large disrupts the normal pattern of lineage segregation. These non-cell-autonomous effects demonstrate that effective airway epithelial regeneration requires intercellular communication within the broader basal stem/progenitor cell population. These findings have broad implications for understanding epithelial regeneration and stem cell heterogeneity. PMID:25658372

  12. Focal expression of mutant huntingtin in the songbird basal ganglia disrupts cortico-basal ganglia networks and vocal sequences.

    PubMed

    Tanaka, Masashi; Singh Alvarado, Jonnathan; Murugan, Malavika; Mooney, Richard

    2016-03-22

    The basal ganglia (BG) promote complex sequential movements by helping to select elementary motor gestures appropriate to a given behavioral context. Indeed, Huntington's disease (HD), which causes striatal atrophy in the BG, is characterized by hyperkinesia and chorea. How striatal cell loss alters activity in the BG and downstream motor cortical regions to cause these disorganized movements remains unknown. Here, we show that expressing the genetic mutation that causes HD in a song-related region of the songbird BG destabilizes syllable sequences and increases overall vocal activity, but leave the structure of individual syllables intact. These behavioral changes are paralleled by the selective loss of striatal neurons and reduction of inhibitory synapses on pallidal neurons that serve as the BG output. Chronic recordings in singing birds revealed disrupted temporal patterns of activity in pallidal neurons and downstream cortical neurons. Moreover, reversible inactivation of the cortical neurons rescued the disorganized vocal sequences in transfected birds. These findings shed light on a key role of temporal patterns of cortico-BG activity in the regulation of complex motor sequences and show how a genetic mutation alters cortico-BG networks to cause disorganized movements. PMID:26951661

  13. Focal expression of mutant huntingtin in the songbird basal ganglia disrupts cortico-basal ganglia networks and vocal sequences

    PubMed Central

    Tanaka, Masashi; Singh Alvarado, Jonnathan; Murugan, Malavika; Mooney, Richard

    2016-01-01

    The basal ganglia (BG) promote complex sequential movements by helping to select elementary motor gestures appropriate to a given behavioral context. Indeed, Huntington’s disease (HD), which causes striatal atrophy in the BG, is characterized by hyperkinesia and chorea. How striatal cell loss alters activity in the BG and downstream motor cortical regions to cause these disorganized movements remains unknown. Here, we show that expressing the genetic mutation that causes HD in a song-related region of the songbird BG destabilizes syllable sequences and increases overall vocal activity, but leave the structure of individual syllables intact. These behavioral changes are paralleled by the selective loss of striatal neurons and reduction of inhibitory synapses on pallidal neurons that serve as the BG output. Chronic recordings in singing birds revealed disrupted temporal patterns of activity in pallidal neurons and downstream cortical neurons. Moreover, reversible inactivation of the cortical neurons rescued the disorganized vocal sequences in transfected birds. These findings shed light on a key role of temporal patterns of cortico-BG activity in the regulation of complex motor sequences and show how a genetic mutation alters cortico-BG networks to cause disorganized movements. PMID:26951661

  14. Prospects for cannabinoid therapies in basal ganglia disorders

    PubMed Central

    Fernández-Ruiz, Javier; Moreno-Martet, Miguel; Rodríguez-Cueto, Carmen; Palomo-Garo, Cristina; Gómez-Cañas, María; Valdeolivas, Sara; Guaza, Carmen; Romero, Julián; Guzmán, Manuel; Mechoulam, Raphael; Ramos, José A

    2011-01-01

    Cannabinoids are promising medicines to slow down disease progression in neurodegenerative disorders including Parkinson's disease (PD) and Huntington's disease (HD), two of the most important disorders affecting the basal ganglia. Two pharmacological profiles have been proposed for cannabinoids being effective in these disorders. On the one hand, cannabinoids like Δ9-tetrahydrocannabinol or cannabidiol protect nigral or striatal neurons in experimental models of both disorders, in which oxidative injury is a prominent cytotoxic mechanism. This effect could be exerted, at least in part, through mechanisms independent of CB1 and CB2 receptors and involving the control of endogenous antioxidant defences. On the other hand, the activation of CB2 receptors leads to a slower progression of neurodegeneration in both disorders. This effect would be exerted by limiting the toxicity of microglial cells for neurons and, in particular, by reducing the generation of proinflammatory factors. It is important to mention that CB2 receptors have been identified in the healthy brain, mainly in glial elements and, to a lesser extent, in certain subpopulations of neurons, and that they are dramatically up-regulated in response to damaging stimuli, which supports the idea that the cannabinoid system behaves as an endogenous neuroprotective system. This CB2 receptor up-regulation has been found in many neurodegenerative disorders including HD and PD, which supports the beneficial effects found for CB2 receptor agonists in both disorders. In conclusion, the evidence reported so far supports that those cannabinoids having antioxidant properties and/or capability to activate CB2 receptors may represent promising therapeutic agents in HD and PD, thus deserving a prompt clinical evaluation. LINKED ARTICLES This article is part of a themed issue on Cannabinoids in Biology and Medicine. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.163.issue-7 PMID:21545415

  15. Long-noncoding RNAs in basal cell carcinoma.

    PubMed

    Sand, Michael; Bechara, Falk G; Sand, Daniel; Gambichler, Thilo; Hahn, Stephan A; Bromba, Michael; Stockfleth, Eggert; Hessam, Schapoor

    2016-08-01

    Long noncoding RNAs (lncRNAs) are fundamental regulators of pre- and post-transcriptional gene regulation. Over 35,000 different lncRNAs have been described with some of them being involved in cancer formation. The present study was initiated to describe differentially expressed lncRNAs in basal cell carcinoma (BCC). Patients with BCC (n = 6) were included in this study. Punch biopsies were harvested from the tumor center and nonlesional epidermal skin (NLES, control, n = 6). Microarray-based lncRNA and mRNA expression profiles were identified through screening for 30,586 lncRNAs and 26,109 protein-coding transcripts (mRNAs). The microarray data were validated by RT-PCR in a second set of BCC versus control samples. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of mRNAs were performed to assess biologically relevant pathways. A total of 1851 lncRNAs were identified as being significantly up-regulated, whereas 2165 lncRNAs were identified as being significantly down-regulated compared to nonlesional skin (p < 0.05). Oncogenic and/or epidermis-specific lncRNAs, such as CASC15 or ANRIL, were among the differentially expressed sequences. GO analysis showed that the highest enriched GO targeted by up-regulated transcripts was "extracellular matrix." KEGG pathway analysis showed the highest enrichment scores in "Focal adhesion." BCC showed a significantly altered lncRNA and mRNA expression profile. Dysregulation of previously described lncRNAs may play a role in the molecular pathogenesis of BCC and should be subject of further analysis. PMID:26861560

  16. Facial dermis grafts after removal of basal cell carcinomas.

    PubMed

    Han, Seung-Kyu; Yoon, Won-Young; Jeong, Seong-Ho; Kim, Woo-Kyung

    2012-11-01

    Selecting a proper reconstruction method is the key to success in skin cancer management, especially for lesions involving the face. Using a skin graft is usually straightforward when covering a skin defect; however, major concerns in skin grafting include a poor color match in the recipient-site and donor-site morbidity. To overcome these limitations, the authors have developed a dermis graft, which utilizes a de-epithelialized split-thickness skin graft method. The purpose of this retrospective study was to report reliability of dermis grafts after removal of basal cell carcinomas (BCCs) on the face by presenting our clinical experience with them. This study included 38 patients who were treated for facial defects created by resection of BCCs. The locations of the defects were as follows: nose (n = 17), orbital area (n = 14), cheek (n = 4), temple area (n = 2), and forehead (n = 1). The defects ranged in size from 3.3 to 6.5 cm. Functional and cosmetic outcomes, postoperative complications, and patient satisfaction were assessed. The patients were followed up for 12 to 36 months. The entire dermis graft re-epithelialized after grafting within 17 to 27 days. Most of the patients had satisfactory results in both functional and cosmetic matters with high-quality skin characteristics. There were no significant complications and no recurrences were observed during the follow-up period. Patient satisfaction with the dermis graft was also excellent. The dermis graft may be used reliably for covering defects after removal of BCCs on the face. PMID:23172436

  17. Basal forebrain projections to the lateral habenula modulate aggression reward.

    PubMed

    Golden, Sam A; Heshmati, Mitra; Flanigan, Meghan; Christoffel, Daniel J; Guise, Kevin; Pfau, Madeline L; Aleyasin, Hossein; Menard, Caroline; Zhang, Hongxing; Hodes, Georgia E; Bregman, Dana; Khibnik, Lena; Tai, Jonathan; Rebusi, Nicole; Krawitz, Brian; Chaudhury, Dipesh; Walsh, Jessica J; Han, Ming-Hu; Shapiro, Matt L; Russo, Scott J

    2016-06-30

    Maladaptive aggressive behaviour is associated with a number of neuropsychiatric disorders and is thought to result partly from the inappropriate activation of brain reward systems in response to aggressive or violent social stimuli. Nuclei within the ventromedial hypothalamus, extended amygdala and limbic circuits are known to encode initiation of aggression; however, little is known about the neural mechanisms that directly modulate the motivational component of aggressive behaviour. Here we established a mouse model to measure the valence of aggressive inter-male social interaction with a smaller subordinate intruder as reinforcement for the development of conditioned place preference (CPP). Aggressors develop a CPP, whereas non-aggressors develop a conditioned place aversion to the intruder-paired context. Furthermore, we identify a functional GABAergic projection from the basal forebrain (BF) to the lateral habenula (lHb) that bi-directionally controls the valence of aggressive interactions. Circuit-specific silencing of GABAergic BF-lHb terminals of aggressors with halorhodopsin (NpHR3.0) increases lHb neuronal firing and abolishes CPP to the intruder-paired context. Activation of GABAergic BF-lHb terminals of non-aggressors with channelrhodopsin (ChR2) decreases lHb neuronal firing and promotes CPP to the intruder-paired context. Finally, we show that altering inhibitory transmission at BF-lHb terminals does not control the initiation of aggressive behaviour. These results demonstrate that the BF-lHb circuit has a critical role in regulating the valence of inter-male aggressive behaviour and provide novel mechanistic insight into the neural circuits modulating aggression reward processing. PMID:27357796

  18. Erosion and basal forces in granular flow experiments

    NASA Astrophysics Data System (ADS)

    Sanvitale, Nicoletta; Bowman, Elisabeth

    2016-04-01

    Extreme mass wasting avalanche events such as rock, snow and ice avalanches, debris flows, and pyroclastic flows are among the most hazardous geological phenomena. These events driven by gravity, can travel for long distance and high speed, increasing their volumes as they can entertain material along their path. The erosion of material and its entrainment can greatly affect the overall dynamics of transportation, either enhancing or impeding the avalanche mobility depending on flow dynamics and characteristics of the substrate. However, the mechanisms and processes acting at the base as they travel over deformable or erodible substrates are still poor understood. Experiments, simulations and field measurements indicate that large fluctuations can occur in basal forces and stresses, which may be the result of non-uniform load transfer within the mass, and rolling, bouncing and sliding of the particles along the bed. In dense granular materials, force distributions can propagate through filamentary chain structures that carry a large fraction of the forces within the system. Photoelastic experiments on two-dimensional, monodisperse, gravity-driven flows have shown that force chains can transmit high localized forces to the boundary of dense granular flows. Here we describe the preliminary setup and results of 2D experiments on polydisperse granular flows of photoelastic disks down a small flume designed to acquire the forces exerted at the boundaries of the flow and to analyze their effects on an erodible bed. The intended outcome of this research is to provide better information on the complex mechanism of erosion and its effects on avalanche behaviour.

  19. Basal ganglia—thalamus and the “crowning enigma”

    PubMed Central

    Garcia-Munoz, Marianela; Arbuthnott, Gordon W.

    2015-01-01

    When Hubel (1982) referred to layer 1 of primary visual cortex as “… a ‘crowning mystery’ to keep area-17 physiologists busy for years to come …” he could have been talking about any cortical area. In the 80’s and 90’s there were no methods to examine this neuropile on the surface of the cortex: a tangled web of axons and dendrites from a variety of different places with unknown specificities and doubtful connections to the cortical output neurons some hundreds of microns below. Recently, three changes have made the crowning enigma less of an impossible mission: the clear presence of neurons in layer 1 (L1), the active conduction of voltage along apical dendrites and optogenetic methods that might allow us to look at one source of input at a time. For all of those reasons alone, it seems it is time to take seriously the function of L1. The functional properties of this layer will need to wait for more experiments but already L1 cells are GAD67 positive, i.e., inhibitory! They could reverse the sign of the thalamic glutamate (GLU) input for the entire cortex. It is at least possible that in the near future normal activity of individual sources of L1 could be detected using genetic tools. We are at the outset of important times in the exploration of thalamic functions and perhaps the solution to the crowning enigma is within sight. Our review looks forward to that solution from the solid basis of the anatomy of the basal ganglia output to motor thalamus. We will focus on L1, its afferents, intrinsic neurons and its influence on responses of pyramidal neurons in layers 2/3 and 5. Since L1 is present in the whole cortex we will provide a general overview considering evidence mainly from the somatosensory (S1) cortex before focusing on motor cortex. PMID:26582979

  20. Redefinition and global estimation of basal ecosystem respiration rate

    USGS Publications Warehouse

    Yuan, W.; Luo, Y.; Li, X.; Liu, S.; Yu, G.; Zhou, T.; Bahn, M.; Black, A.; Desai, A.R.; Cescatti, A.; Marcolla, B.; Jacobs, C.; Chen, J.; Aurela, M.; Bernhofer, C.; Gielen, B.; Bohrer, G.; Cook, D.R.; Dragoni, D.; Dunn, A.L.; Gianelle, D.; Grnwald, T.; Ibrom, A.; Leclerc, M.Y.; Lindroth, A.; Liu, H.; Marchesini, L.B.; Montagnani, L.; Pita, G.; Rodeghiero, M.; Rodrigues, A.; Starr, G.; Stoy, P.C.

    2011-01-01

    Basal ecosystem respiration rate (BR), the ecosystem respiration rate at a given temperature, is a common and important parameter in empirical models for quantifying ecosystem respiration (ER) globally. Numerous studies have indicated that BR varies in space. However, many empirical ER models still use a global constant BR largely due to the lack of a functional description for BR. In this study, we redefined BR to be ecosystem respiration rate at the mean annual temperature. To test the validity of this concept, we conducted a synthesis analysis using 276 site-years of eddy covariance data, from 79 research sites located at latitudes ranging from ???3S to ???70N. Results showed that mean annual ER rate closely matches ER rate at mean annual temperature. Incorporation of site-specific BR into global ER model substantially improved simulated ER compared to an invariant BR at all sites. These results confirm that ER at the mean annual temperature can be considered as BR in empirical models. A strong correlation was found between the mean annual ER and mean annual gross primary production (GPP). Consequently, GPP, which is typically more accurately modeled, can be used to estimate BR. A light use efficiency GPP model (i.e., EC-LUE) was applied to estimate global GPP, BR and ER with input data from MERRA (Modern Era Retrospective-Analysis for Research and Applications) and MODIS (Moderate resolution Imaging Spectroradiometer). The global ER was 103 Pg C yr -1, with the highest respiration rate over tropical forests and the lowest value in dry and high-latitude areas. Copyright 2011 by the American Geophysical Union.

  1. Laboratory Study of the Frictional Properties of Simulated Basal ice

    NASA Astrophysics Data System (ADS)

    Emerson, L.; Rempel, A.

    2006-12-01

    Sediment entrained in ice modifies the shear traction beneath warm-based glaciers. In an attempt to understand how entrained sediment affects the frictional behavior of melting ice against hard, impermeable substrates, we conducted a series of constant-velocity sliding experiments. We simulate basal ice by freezing sediment particles with controlled size distributions and concentrations into ice disks. Our sliding apparatus is driven by a motor coupled to a lead ball screw which displaces a carriage secured by two additional bearing rods. This design increases apparatus stiffness. The normal force was applied with a series of dead weights and the shear force was recorded with a gauge linked to the sliding carriage. The ratio of the measured shear force to the applied normal force produces an effective friction coefficient. Two regimes of frictional behavior are observed. The first, we call slippery, exhibits effective friction coefficients approaching zero and is indistinguishable from the debris free ice used as a control. The second, we call sandy, is indistinguishable from a sand block used as a control, has friction coefficients near 0.3, and high variability. Our results demonstrate that at higher particle loadings, the transition between these regimes occurs when the particle diameter approaches the thickness of the water layer between the ice and sliding surface. The thickness of the water layer is inferred from lubrication theory as a function of the melt rate and normal force, both measured experimental parameters. A similar transition from sandy to slippery with larger particle sizes is observed at low particle concentrations. This effect is likely related to the inability of the fluid above the particle to maintain a pressure gradient sufficient to transmit the imposed normal load to the particles and thus produce high effective friction coefficients.

  2. Quantitation of the human basal ganglia with Positron Emission Tomography

    SciTech Connect

    Bendriem, B.; Dewey, S.L.; Schlyer, D.J.; Wolf, A.P.; Volkow, N.D.

    1990-01-01

    The accurate measurement of the concentration of a radioisotope in small structures with PET requires a correction for quantitation loss due to the partial volume effect and the effect of scattered radiation. To evaluate errors associated with measures in the human basal ganglia (BG) we have built a unilateral model of the BG that we have inserted in a 20 cm cylinder. The recovery coefficient (RC = measured activity/true activity) for our BG phantom has been measured on a CTI tomograph (model 931-08/12) with different background concentrations (contrast) and at different axial locations in the gantry. The BG was visualized on 4 or 5 slices depending on its position in the gantry and on the contrast used. The RC was 0.75 with no background (contrast equal to 1.0). Increasing the relative radioactivity concentration in the background increased the RC from 0.75 to 2.00 when the contrast was {minus}0.7 (BG < Background). The RC was also affected by the size and the shape of the region of interest (ROI) used (RC from 0.75 to 0.67 with ROI size from 0.12 to 1.41 cm{sup 2}). These results show that accurate RC correction depends not only on the volume of the structure but also on its contrast with its surroundings as well as on the selection of the ROI. They also demonstrate that the higher the contrast the more sensitive to axial positioning PET measurements in the BG are. These data provide us with some information about the variability of PET measurements in small structure like the BG and we have proposed some strategies to improve the reproducibility. 18 refs., 3 figs., 5 tabs.

  3. Laser ablation of basal cell carcinomas guided by confocal microscopy

    NASA Astrophysics Data System (ADS)

    Sierra, Heidy; Cordova, Miguel; Nehal, Kishwer; Rossi, Anthony; Chen, Chih-Shan Jason; Rajadhyaksha, Milind

    2016-02-01

    Laser ablation offers precise and fast removal of superficial and early nodular types of basal cell carcinomas (BCCs). Nevertheless, the lack of histological confirmation has been a limitation. Reflectance confocal microscopy (RCM) imaging combined with a contrast agent can offer cellular-level histology-like feedback to detect the presence (or absence) of residual BCC directly on the patient. We conducted an ex vivo bench-top study to provide a set of effective ablation parameters (fluence, number of passes) to remove superficial BCCs while also controlling thermal coagulation post-ablation to allow uptake of contrast agent. The results for an Er:YAG laser (2.9 um and pulse duration 250us) show that with 6 passes of 25 J/cm2, thermal coagulation can be effectively controlled, to allow both the uptake of acetic acid (contrast agent) and detection of residual (or absence) BCCs. Confirmation was provided with histological examination. An initial in vivo study on 35 patients shows that the uptake of contrast agent aluminum chloride) and imaging quality is similar to that observed in the ex vivo study. The detection of the presence of residual tumor or complete clearance was confirmed in 10 wounds with (additional) histology and in 25 lesions with follow-up imaging. Our results indicate that resolution is sufficient but further development and use of appropriate contrast agent are necessary to improve sensitivity and specificity. Advances in RCM technology for imaging of lateral and deep margins directly on the patient may provide less invasive, faster and less expensive image-guided approaches for treatment of BCCs.

  4. Basal melt beneath whillans ice stream and ice streams A and C

    NASA Technical Reports Server (NTRS)

    Joughin, I.; Teluezyk, S.; Engelhardt, H.

    2002-01-01

    We have used a recently derived map of the velocity of Whillans Ice Stream and Ice Streams A and C to help estimate basal melt. Temperature was modeled with a simple vertical advection-diffusion equation, 'tuned' to match temperature profiles. We find that most of the melt occurs beneath the tributaries where larger basal shear stresses and thicker ice favors greater melt (e.g., 10-20 mm/yr). The occurrence of basal freezing is predicted beneath much of the ice plains of Ice Stream C and Whillans Ice Stream. Modelled melt rates for when Ice Stream C was active suggest there was just enough melt water generated in its tributaries to balance basal freezing on its ice plain. Net basal melt for Whillans Ice Stream is positive due to smaller basal temperature gradients. Modelled temperatures on Whillans Ice Stream, however, were constrained by a single temperature profile at UpB. Basal temperature gradients for Whillans B1 and Ice Stream A may have conditions more similar to those beneath Ice Streams C and D, in which case, there may not be sufficient melt to sustain motion. This would be consistent with the steady deceleration of Whillans stream over the last few decades.

  5. Retrieving Ice Basal Motion Using the Hydrologically Coupled JPL/UCI Ice Sheet System Model (ISSM)

    NASA Astrophysics Data System (ADS)

    Khakbaz, B.; Morlighem, M.; Seroussi, H. L.; Larour, E. Y.

    2011-12-01

    The study of basal sliding in ice sheets requires coupling ice-flow models with subglacial water flow. In fact, subglacial hydrology models can be used to model basal water-pressure explicitly and to generate basal sliding velocities. This study addresses the addition of a thin-film-based subglacial hydrologic module to the Ice Sheet System Model (ISSM) developed by JPL in collaboration with the University of California Irvine (UCI). The subglacial hydrology model follows the study of J. Johnson (2002) who assumed a non-arborscent distributed drainage system in the form of a thin film beneath ice sheets. The differential equation that arises from conservation of mass in the water system is solved numerically with the finite element method in order to obtain the spatial distribution of basal water over the study domain. The resulting sheet water thickness is then used to model the basal water-pressure and subsequently the basal sliding velocity. In this study, an introduction and preliminary results of the subglacial water flow and basal sliding velocity will be presented for the Pine Island Glacier west Antarctica.This work was performed at the California Institute of Technology's Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration's Modeling, Analysis and Prediction (MAP) Program.

  6. Parallel basal ganglia circuits for voluntary and automatic behaviour to reach rewards.

    PubMed

    Kim, Hyoung F; Hikosaka, Okihide

    2015-07-01

    The basal ganglia control body movements, value processing and decision-making. Many studies have shown that the inputs and outputs of each basal ganglia structure are topographically organized, which suggests that the basal ganglia consist of separate circuits that serve distinct functions. A notable example is the circuits that originate from the rostral (head) and caudal (tail) regions of the caudate nucleus, both of which target the superior colliculus. These two caudate regions encode the reward values of visual objects differently: flexible (short-term) values by the caudate head and stable (long-term) values by the caudate tail. These value signals in the caudate guide the orienting of gaze differently: voluntary saccades by the caudate head circuit and automatic saccades by the caudate tail circuit. Moreover, separate groups of dopamine neurons innervate the caudate head and tail and may selectively guide the flexible and stable learning/memory in the caudate regions. Studies focusing on manual handling of objects also suggest that rostrocaudally separated circuits in the basal ganglia control the action differently. These results suggest that the basal ganglia contain parallel circuits for two steps of goal-directed behaviour: finding valuable objects and manipulating the valuable objects. These parallel circuits may underlie voluntary behaviour and automatic skills, enabling animals (including humans) to adapt to both volatile and stable environments. This understanding of the functions and mechanisms of the basal ganglia parallel circuits may inform the differential diagnosis and treatment of basal ganglia disorders. PMID:25981958

  7. Are the basal cells of the mammalian epididymis still an enigma?

    PubMed

    Arrighi, S

    2014-10-01

    Basal cells are present in the columnar pseudostratified epithelium covering the epididymis of all mammalian species, which regulates the microenvironment where the functionally incompetent germ cells produced by the testis are matured and stored. Striking novelties have come from investigations on epididymal basal cells in the past 30-40 years. In addition to an earlier hypothesised scavenger role for basal cells, linked to their proven extratubular origin and the expression of macrophage antigens, basal cells have been shown to be involved in cell-cell cross-talk, as well as functioning as luminal sensors to regulate the activity of principal and clear cells. Involvement of basal cells in the regulation of electrolyte and water transport by principal cells was hypothesised. This control is suggested to be mediated by the local formation of prostaglandins. Members of the aquaporin (AQP) and/or aquaglyceroporin family (AQP3, AQP7 and AQP8) are also specifically expressed in the rat epididymal basal cells. Transport of glycerol and glycerylphosphorylcholine from the epithelium of the epididymis to the lumen in relation to sperm maturation may be mediated by AQP. Most probably basal cells collaborate to the building up of the blood-epididymis barrier through cell adhesion molecules, implying an involvement in immune control exerted towards sperm cells, which are foreigners in the environment in which they were produced. PMID:24138802

  8. Ultrastructural observations on the basal lamina in the normal human breast.

    PubMed Central

    Watson, R J; Eyden, B P; Howell, A; Sellwood, R A

    1988-01-01

    The ultrastructure of the basal lamina of histologically normal human breast tissue was determined in 19 women undergoing operations for removal of a fibroadenoma or reduction mammoplasty. The day of the menstrual cycle was determined by hormone assay and direct questioning. Previously documented ultrastructural appearances were confirmed: in addition, three morphological variants were found. In all tissue examined, there was reduplication of basal lamina in some areas, which has been described previously as a pathological feature. Also, there was complex branching of the basal lamina into the periductular connective tissue. Some projections contained cytoplasmic processes and, in almost all, hemidesmosomes were seen. The third variant consisted of loops of basal lamina thrown up in folds into the collagenous stromal cuff. Reduplication of basal lamina was detected in breast tissue removed at all stages of the menstrual cycle, looping was not and could not be related to any particular phase of the menstrual cycle. However, complex branching was seen predominantly in the periovulatory and early luteal phase. We conclude that these appearances are normal variants of basal lamina. The appearance of branching basal lamina in the luteal phase suggests that this may be produced in response to endocrine stimulation. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:3417540

  9. Basal Forebrain Atrophy Contributes to Allocentric Navigation Impairment in Alzheimer’s Disease Patients

    PubMed Central

    Kerbler, Georg M.; Nedelska, Zuzana; Fripp, Jurgen; Laczó, Jan; Vyhnalek, Martin; Lisý, Jiří; Hamlin, Adam S.; Rose, Stephen; Hort, Jakub; Coulson, Elizabeth J.

    2015-01-01

    The basal forebrain degenerates in Alzheimer’s disease (AD) and this process is believed to contribute to the cognitive decline observed in AD patients. Impairment in spatial navigation is an early feature of the disease but whether basal forebrain dysfunction in AD is responsible for the impaired navigation skills of AD patients is not known. Our objective was to investigate the relationship between basal forebrain volume and performance in real space as well as computer-based navigation paradigms in an elderly cohort comprising cognitively normal controls, subjects with amnestic mild cognitive impairment and those with AD. We also tested whether basal forebrain volume could predict the participants’ ability to perform allocentric- vs. egocentric-based navigation tasks. The basal forebrain volume was calculated from 1.5 T magnetic resonance imaging (MRI) scans, and navigation skills were assessed using the human analog of the Morris water maze employing allocentric, egocentric, and mixed allo/egocentric real space as well as computerized tests. When considering the entire sample, we found that basal forebrain volume correlated with spatial accuracy in allocentric (cued) and mixed allo/egocentric navigation tasks but not the egocentric (uncued) task, demonstrating an important role of the basal forebrain in mediating cue-based spatial navigation capacity. Regression analysis revealed that, although hippocampal volume reflected navigation performance across the entire sample, basal forebrain volume contributed to mixed allo/egocentric navigation performance in the AD group, whereas hippocampal volume did not. This suggests that atrophy of the basal forebrain contributes to aspects of navigation impairment in AD that are independent of hippocampal atrophy. PMID:26441643

  10. The Basal Onaping Intrusion in the North Range: Roof rocks of the Sudbury Igneous Complex

    NASA Astrophysics Data System (ADS)

    Anders, Denise; Osinski, Gordon R.; Grieve, Richard A. F.; Brillinger, Derek T. M.

    2015-09-01

    The 1.85 Ga Sudbury impact structure is one of the largest impact structures on Earth. Igneous bodies—the so-called "Basal Onaping Intrusion"—occur at the contact between the Sudbury Igneous Complex (SIC) and the overlying Onaping Formation and occupy ~50% of this contact zone. The Basal Onaping Intrusion is presently considered part of the Onaping Formation, which is a complex series of breccias. Here, we present petrological and geochemical data from two drill cores and field data from the North Range of the Sudbury structure, which suggests that the Basal Onaping Intrusion is not part of the Onaping Formation. Our observations indicate that the Basal Onaping Intrusion crystallized from a melt and has a groundmass comprising a skeletal intergrowth of feldspar and quartz that points to simultaneous cooling of both components. Increasing grain size and decreasing amounts of clasts with increasing depth are general features of roof rocks of coherent impact melt rocks at other impact structures and the Basal Onaping Intrusion. Planar deformation features within quartz clasts of the Basal Onaping Intrusion are indicators for shock metamorphism and, together with the melt matrix, point to the Basal Onaping Intrusion as being an impact melt rock, by definition. Importantly, the contact between Granophyre of the SIC and Basal Onaping Intrusion is transitional and we suggest that the Basal Onaping Intrusion is what remains of the roof rocks of the SIC and, thus, is a unit of the SIC and not the Onaping Formation. We suggest henceforth that this unit be referred to as the "Upper Contact Unit" of the SIC.

  11. Basal Forebrain Atrophy Contributes to Allocentric Navigation Impairment in Alzheimer's Disease Patients.

    PubMed

    Kerbler, Georg M; Nedelska, Zuzana; Fripp, Jurgen; Laczó, Jan; Vyhnalek, Martin; Lisý, Jiří; Hamlin, Adam S; Rose, Stephen; Hort, Jakub; Coulson, Elizabeth J

    2015-01-01

    The basal forebrain degenerates in Alzheimer's disease (AD) and this process is believed to contribute to the cognitive decline observed in AD patients. Impairment in spatial navigation is an early feature of the disease but whether basal forebrain dysfunction in AD is responsible for the impaired navigation skills of AD patients is not known. Our objective was to investigate the relationship between basal forebrain volume and performance in real space as well as computer-based navigation paradigms in an elderly cohort comprising cognitively normal controls, subjects with amnestic mild cognitive impairment and those with AD. We also tested whether basal forebrain volume could predict the participants' ability to perform allocentric- vs. egocentric-based navigation tasks. The basal forebrain volume was calculated from 1.5 T magnetic resonance imaging (MRI) scans, and navigation skills were assessed using the human analog of the Morris water maze employing allocentric, egocentric, and mixed allo/egocentric real space as well as computerized tests. When considering the entire sample, we found that basal forebrain volume correlated with spatial accuracy in allocentric (cued) and mixed allo/egocentric navigation tasks but not the egocentric (uncued) task, demonstrating an important role of the basal forebrain in mediating cue-based spatial navigation capacity. Regression analysis revealed that, although hippocampal volume reflected navigation performance across the entire sample, basal forebrain volume contributed to mixed allo/egocentric navigation performance in the AD group, whereas hippocampal volume did not. This suggests that atrophy of the basal forebrain contributes to aspects of navigation impairment in AD that are independent of hippocampal atrophy. PMID:26441643

  12. Floral gene resources from basal angiosperms for comparative genomics research

    PubMed Central

    Albert, Victor A; Soltis, Douglas E; Carlson, John E; Farmerie, William G; Wall, P Kerr; Ilut, Daniel C; Solow, Teri M; Mueller, Lukas A; Landherr, Lena L; Hu, Yi; Buzgo, Matyas; Kim, Sangtae; Yoo, Mi-Jeong; Frohlich, Michael W; Perl-Treves, Rafael; Schlarbaum, Scott E; Bliss, Barbara J; Zhang, Xiaohong; Tanksley, Steven D; Oppenheimer, David G; Soltis, Pamela S; Ma, Hong; dePamphilis, Claude W; Leebens-Mack, James H

    2005-01-01

    Background The Floral Genome Project was initiated to bridge the genomic gap between the most broadly studied plant model systems. Arabidopsis and rice, although now completely sequenced and under intensive comparative genomic investigation, are separated by at least 125 million years of evolutionary time, and cannot in isolation provide a comprehensive perspective on structural and functional aspects of flowering plant genome dynamics. Here we discuss new genomic resources available to the scientific community, comprising cDNA libraries and Expressed Sequence Tag (EST) sequences for a suite of phylogenetically basal angiosperms specifically selected to bridge the evolutionary gaps between model plants and provide insights into gene content and genome structure in the earliest flowering plants. Results Random sequencing of cDNAs from representatives of phylogenetically important eudicot, non-grass monocot, and gymnosperm lineages has so far (as of 12/1/04) generated 70,514 ESTs and 48,170 assembled unigenes. Efficient sorting of EST sequences into putative gene families based on whole Arabidopsis/rice proteome comparison has permitted ready identification of cDNA clones for finished sequencing. Preliminarily, (i) proportions of functional categories among sequenced floral genes seem representative of the entire Arabidopsis transcriptome, (ii) many known floral gene homologues have been captured, and (iii) phylogenetic analyses of ESTs are providing new insights into the process of gene family evolution in relation to the origin and diversification of the angiosperms. Conclusion Initial comparisons illustrate the utility of the EST data sets toward discovery of the basic floral transcriptome. These first findings also afford the opportunity to address a number of conspicuous evolutionary genomic questions, including reproductive organ transcriptome overlap between angiosperms and gymnosperms, genome-wide duplication history, lineage-specific gene duplication and

  13. Myxosporean hyperparasites of gill monogeneans are basal to the Multivalvulida

    PubMed Central

    2011-01-01

    Background Myxosporeans are known from aquatic annelids but parasitism of platyhelminths by myxosporeans has not been widely reported. Hyperparasitism of gill monogeneans by Myxidium giardi has been reported from the European eel and Myxidium-like hyperparasites have also been observed during studies of gill monogeneans from Malaysia and Japan. The present study aimed to collect new hyperparasite material from Malaysia for morphological and molecular descriptions. In addition, PCR screening of host fish was undertaken to determine whether they are also hosts for the myxosporean. Results Heavy myxosporean infections were observed in monogeneans from two out of 14 fish and were detected from a further five fish using specific PCRs and pooled monogenean DNA. Positive DNA isolates were sequenced and were from a single species of myxosporean. Myxospore morphology was consistent with Myxidium with histozoic development in the parenchymal tissues of the monogenean. Simultaneous infections in the fish could not be confirmed microscopically; however, identical myxosporean DNA could be amplified from kidney, spleen and intestinal tract tissues using the specific PCR. Small subunit (SSU) rDNA for the myxosporean was amplified and was found to be most similar (92%) to that of another hyperparasitic myxosporean from a gill monogenean from Japan and to numerous multivalvulidan myxosporeans from the genus Kudoa (89-91%). Phylogenetic analyses placed the hyperparasite sequence basally to clades containing Kudoa, Unicapsula and Sphaerospora. Conclusions The myxosporean infecting the gill monogenean, Diplectanocotyla gracilis, from the Indo-Pacific tarpon, Megalops cyprinoides, is described as a new species, Myxidium incomptavermi, based on a histozoic development in the monogenean host and its phylogenetic placement. We have demonstrated for the first time that a myxosporean hyperparasite of gill monogeneans is detectable in the fish host. However, myxospores could not be isolated

  14. [Basal cell carcinoma of prostate: a report of three cases].

    PubMed

    Liu, Z; Ma, L L; Zhang, S D; Lu, M; Tian, Y; He, Q; Jin, J

    2016-02-18

    To explore the clinical pathological characteristics and improve the recognition in the diagnosis and treatment of basal cell carcinoma (BCC) of prostate. Three cases of BCC of prostate were reported and the relevant literature was reviewed to investigate the diagnosis and treatment of this disease. We analyzed three cases of prostatic BCC. Their ages were within a range of 57 to 83 years. One of them complained of hematuria and two complained of dysuria. All of them presented with prostatic hyperplasia. Two of them presented with high prostate specific antigen (PSA) and one with normal PSA. Case 1 had prostate cancer invasion of bladder, rectal fascia, with lymph node metastasis, bone metastasis and lung metastases. The patient received bladder resection+bilateral ureteral cutaneous ureterostomy+lymph node dissection on November 2, 2014 . Postoperative pathological diagnosis showed BCC. Reexamination of pelvic enhanced MRI in January 8, 2015 suggested pelvic recurrence. Abdominal enhanced CT showed multiple liver metastases and pancreatic metastasis on July 11, 2015. Prostate cancer specific death occurred in October 2015. Case 2 was diagnosed as BCC in prostate biopsy on March 27, 2015. Positron emission tomography and computed tomography (PET-CT) showed pulmonary metastasis and bone metastasis. Then the patient received chemotherapy, endocrine therapy and local radiation therapy. Reexamination of PET-CT on January 11, 2016 showed that the lung metastase tumors and bone metastase tumors were larger than before. Up to January 10, 2016, the patient was still alive. Postoperative pathological changes of transurethral resection of prostate (TURP) in case 3 showed BCC might be considered. The PET-CT suggested residual prostate cancer, which might be associated with bilateral pelvic lymph node metastasis. In April 20, 2016, the review of PET-CT showed pelvic huge irregular hybrid density shadow, about 14.5 cm×10.0 cm×12.9 cm in size, and tumor recurrence was

  15. The Basal Ganglia as a Substrate for the Multiple Actions of Amphetamines

    PubMed Central

    Natarajan, Reka; Yamamoto, Bryan K.

    2011-01-01

    Amphetamines are psychostimulant drugs with high abuse potential. Acute and chronic doses of amphetamines affect dopamine (DA) neurotransmission in the basal ganglia. The basal ganglia are a group of subcortical nuclei that are anatomically positioned to integrate cognitive, motor and sensorimotor inputs from the cortex. Amphetamines can differentially alter the functioning of specific BG circuits to produce neurochemical changes that affect cognition, movement, and drug seeking behavior through their effects on DA neurotransmission. This review focuses on how alterations in dopaminergic neurotransmission within distinct basal ganglia pathways can modify their functional output to predict and explain the acute and long term behavioral consequences of amphetamine exposure. PMID:21804952

  16. PD-L1 Expression Is Increased in a Subset of Basal Type Breast Cancer Cells

    PubMed Central

    Soliman, Hatem; Khalil, Farah; Antonia, Scott

    2014-01-01

    Background Tumor cells express programmed death ligand 1 (PD-L1) and is a key immune evasion mechanism. PD-L1 expression in multiple breast cancer cell lines was evaluated to identify intrinsic differences that affect their potential for immune evasion. Methods PD-L1 expression was analyzed in six breast cancer cell lines: AU565&MCF7 (luminal), BT20&HCC1143 (basal A), MDA231&HCC38 (basal B). Surface and intracellular PD-L1 expression +/− interferon γ for 48 hours was measured by flow cytometry. PD-L1 gene expression data for all breast cancer cell lines in the Comprehensive Cell Line Encyclopedia (CCLE) was analyzed. Correlation between PD-L1 levels and clinicopathologic parameters was analyzed within Oncomine datasets. A tissue microarray containing 61 invasive breast cancer primary tumor cores was stained for PD-L1 expression and analyzed. Results Basal breast cancer cells constitutively express the highest levels of PD-L1. All cell lines increased PD-L1 expression with interferon γ, but basal B cells (MDA-231 and HCC38) demonstrated the largest increases. There were no differences in protein localization between cell lines. In the CCLE data, basal cell lines demonstrated higher mean PD-L1 expression compared to luminal cell lines. High PD-L1 expressing basal cell lines over-express genes involved in invasion, proliferation, and chemoresistance compared to low PD-L1 basal cell lines. High PD-L1 basal cell lines had lower expression of IRF2BP2 and higher STAT1 levels compared to low PD-L1 expressing cell lines. Within Oncomine datasets PDL1 mRNA levels were higher in basal type tumors. The TMA analysis demonstrated that lymph node positive cases had higher levels of PD-L1 protein expression compared to lymph node negative cases. Conclusions Basal type breast cancer (especially basal B) express greater levels of PD-L1 constitutively and with IFN γ. High PD-L1 basal cells over-express genes involved in invasion, motility, and chemoresistance. Targeting PD-L1

  17. Basal buoyancy and fast-moving glaciers: in defense of analytic force balance

    NASA Astrophysics Data System (ADS)

    van der Veen, C. J.

    2016-06-01

    The geometric approach to force balance advocated by T. Hughes in a series of publications has challenged the analytic approach by implying that the latter does not adequately account for basal buoyancy on ice streams, thereby neglecting the contribution to the gravitational driving force associated with this basal buoyancy. Application of the geometric approach to Byrd Glacier, Antarctica, yields physically unrealistic results, and it is argued that this is because of a key limiting assumption in the geometric approach. A more traditional analytic treatment of force balance shows that basal buoyancy does not affect the balance of forces on ice streams, except locally perhaps, through bridging effects.

  18. Reversible Acute Parkinsonism and Bilateral Basal Ganglia Lesions in a Diabetic Uremic Patient

    PubMed Central

    Nzwalo, Hipólito; Sá, Francisca; Capela, Carlos; Ferreira, Fátima; Basílio, Carlos

    2012-01-01

    The syndrome of bilateral basal ganglia lesions in diabetic uremic patients is a rare disorder mostly reported in Asians. There are few reports of the syndrome in Caucasians. It manifests as an acute hyperkinetic or hypokinetic extrapyramidal disorder in association with uniform neuroimaging findings of bilateral symmetrical basal ganglia changes in diabetics undergoing hemodialysis. Its pathophysiology remains largely unknown. Thus, we report a typical case of the syndrome in a Caucasian patient who developed an acute and reversible akinetic rigid parkinsonism secondary to bilateral basal ganglia lesions. PMID:23185167

  19. Heat-transfer analysis of the basal melting of Antarctic ice shelves

    SciTech Connect

    Minale, M.; Astarita, G.

    1993-12-01

    Basal melting of Antarctic ice shelves is an important element in the overall balance of Antarctic ice. A heat-transfer model for the basal melting of the Drygalski Ice Tongue is presented. The model does not contain any adjustable parameter. The calculated basal melting rate agrees very well with the value estimated from an overall ice balance on the ice tongue. It is concluded that relatively simple concepts of transport phenomena may be used to model some important features of the dynamics of the Antarctic ice sheet.

  20. Comparison of computer-integrated patient-controlled epidural analgesia with no initial basal infusion versus moderate basal infusion for labor and delivery: A randomized controlled trial

    PubMed Central

    Sng, Ban Leong; Woo, David; Leong, Wan Ling; Wang, Hao; Assam, Pryseley Nkouibert; Sia, Alex TH

    2014-01-01

    Background and Aims: Computer-integrated patient-controlled epidural analgesia (CIPCEA) is a novel epidural drug delivery system. It automatically adjusts the basal infusion based on the individual's need for analgesia as labor progresses. Materials and Methods: This study compared the time-weighted local anesthetic (LA) consumption by comparing parturients using CIPCEA with no initial basal infusion (CIPCEA0) with CIPCEA with initial moderate basal infusion of 5 ml/H (CIPCEA5). We recruited 76 subjects after ethics approval. The computer integration of CIPCEA titrate the basal infusion to 5, 10, 15, or 20 ml/H if the parturient required respectively, one, two, three, or four patient demands in the previous hour. The basal infusion reduced by 5 ml/H if there was no demand in the previous hour. The sample size was calculated to show equivalence in LA consumption. Results: The time-weighted LA consumption between both groups were similar with CIPCEA0 group (mean [standard deviation (SD)] 8.9 [3.5] mg/H) compared to the CIPCEA5 group (mean [SD] 9.9 [3.5] mg/H), P = 0.080. Both groups had a similar incidence of breakthrough pain, duration of the second stage, mode of delivery, and patient satisfaction. However, more subjects in the CIPCEA0 group required patient self-bolus. There were no differences in fetal outcomes. Discussion: Both CIPCEA regimens had similar time-weighted LA consumption and initial moderate basal infusion with CIPCEA may not be required. PMID:25425774

  1. Basal cell adenoma of the parotid gland. Case report and review of the literature.

    PubMed

    González-García, Raúl; Nam-Cha, Syong H; Muñoz-Guerra, Mario F; Gamallo-Amat, C

    2006-03-01

    Basal cell adenoma of the salivary glands is an uncommon type of monomorphous adenoma. Its most frequent location is the parotid gland. It usually appears as a firm and mobile slow-growing mass. Histologically, isomorphic cells in nests and interlaced trabecules with a prominent basal membrane are observed. It is also characterized by the presence of a slack and hyaline stroma and the absence of myxoid or condroid stroma. In contrast to pleomorphic adenoma, it tends to be multiple and its recurrence rate after surgical excision is high. Due to prognostic implications, differential diagnosis with basal cell adenocarcinoma, adenoid cystic carcinoma and basaloid squamous cell carcinoma is mandatory. We describe a case of basal cell adenoma of the parotid gland. We also review the literature and discuss the diagnosis and management of this rare entity. PMID:16505803

  2. Estimating basal friction in accretionary wedges from the geometry and spacing of frontal faults

    NASA Astrophysics Data System (ADS)

    Schott, Bertram; Koyi, Hemin A.

    2001-12-01

    Elastic theory applied to the deformation in accretionary wedges is used to calculate the condition for slip along an active frontal fault and the basal décollement. The equations for calculating the stresses can be solved for the coefficient of basal friction in the situation of the formation of a new frontal thrust fault. This allows us to calculate the efficient coefficient of basal friction, which includes the weakening effect of pore-fluid pressure, from geometric parameters and material properties only. The geometric parameters, like fault dip and layer thickness, can be derived from high-resolution seismic cross-sections. Application of our analysis to the Makran and the Nankai accretionary wedge allows us to estimate the upper limit of the effective coefficient of basal friction, μb≈0.16 and μb≈0.2, in these two areas respectively.

  3. Bilateral Traumatic Basal Ganglia Hemorrhage Associated With Epidural Hematoma: Case Report and Literature Review

    PubMed Central

    Calderon-Miranda, Willem Guillermo; Alvis-Miranda, Hernando Raphael; Alcala-Cerra, Gabriel; M. Rubiano, Andres; Moscote-Salazar, Luis Rafael

    2014-01-01

    Traumatic basal ganglia hematoma is a rare condition defined as presence of hemorrhagic lesions in basal ganglia or adjacent structures suchas internal capsule, putamen and thalamus. Bilateral basal ganglia hematoma are among the devastating and rare condition. We herein report a 28-year old man, a victim of car-car accident who was brought to our surgical emergency room by immediate loss of consciousness and was diagnosed to have hyperdense lesion in the basal ganglia bilaterally, with the presence of right parietal epidural hematoma. Craniotomy and epidural hematoma drainage were considered, associated to conservative management of gangliobasal traumatic contusions. On day 7 the patient had sudden neurologic deterioration, cardiac arrest unresponsive to resuscitation. Management of these lesions is similar to any other injury in moderate to severe traumatic injury. The use of intracranial pressure monitoring must be guaranteed. PMID:27162882

  4. Bilateral Traumatic Basal Ganglia Hemorrhage Associated With Epidural Hematoma: Case Report and Literature Review.

    PubMed

    Calderon-Miranda, Willem Guillermo; Alvis-Miranda, Hernando Raphael; Alcala-Cerra, Gabriel; M Rubiano, Andres; Moscote-Salazar, Luis Rafael

    2014-07-01

    Traumatic basal ganglia hematoma is a rare condition defined as presence of hemorrhagic lesions in basal ganglia or adjacent structures suchas internal capsule, putamen and thalamus. Bilateral basal ganglia hematoma are among the devastating and rare condition. We herein report a 28-year old man, a victim of car-car accident who was brought to our surgical emergency room by immediate loss of consciousness and was diagnosed to have hyperdense lesion in the basal ganglia bilaterally, with the presence of right parietal epidural hematoma. Craniotomy and epidural hematoma drainage were considered, associated to conservative management of gangliobasal traumatic contusions. On day 7 the patient had sudden neurologic deterioration, cardiac arrest unresponsive to resuscitation. Management of these lesions is similar to any other injury in moderate to severe traumatic injury. The use of intracranial pressure monitoring must be guaranteed. PMID:27162882

  5. Imaging of basal cell carcinoma tissue using en-face OCT

    NASA Astrophysics Data System (ADS)

    Penmetsa, Bhanu Rakesh; Khandwala, Mona; Bradu, Adrian; Hughes, Michael; Jones, Carole A.; Schofield, John; Podoleanu, Adrian Gh.

    2008-09-01

    We have investigated the applicability of en-face OCT in imaging freshly excised biopsies of Basal Cell Carcinoma. Encouraging results have been obtained in identifying tumor features and abnormal skin architecture.

  6. Validation of Algorithms for Basal Insulin Rate Reductions in Type 1 Diabetic Patients Practising Physical Activity

    ClinicalTrials.gov

    2013-04-19

    Type 1 Diabetes With a Subcutaneous Insulin Pump; Adjustment of the Recommended Basal Insulin Flow Rate in the Event of Physical Activity; Adjustment of the Recommended Prandial Insulin in the Event of Physical Activity

  7. Anatomy of a songbird basal ganglia circuit essential for vocal learning and plasticity

    PubMed Central

    Gale, Samuel D.; Perkel, David J.

    2009-01-01

    Vocal learning in songbirds requires an anatomically discrete and functionally dedicated circuit called the anterior forebrain pathway (AFP). The AFP is homologous to cortico-basal ganglia-thalamo-cortical loops in mammals. The basal ganglia portion of this pathway, Area X, shares many features characteristic of the mammalian striatum and pallidum, including cell-types and connectivity. The AFP also deviates from mammalian basal ganglia circuits in fundamental ways. In addition, the microcircuitry, role of neuromodulators, and function of Area X are still unclear. Elucidating the mechanisms by which both mammalian-like and unique features of the AFP contribute to vocal learning may help lead to a broad understanding of the sensorimotor functions of basal ganglia circuits. PMID:19596062

  8. Clonal Dynamics Reveal Two Distinct Populations of Basal Cells in Slow-Turnover Airway Epithelium.

    PubMed

    Watson, Julie K; Rulands, Steffen; Wilkinson, Adam C; Wuidart, Aline; Ousset, Marielle; Van Keymeulen, Alexandra; Göttgens, Berthold; Blanpain, Cédric; Simons, Benjamin D; Rawlins, Emma L

    2015-07-01

    Epithelial lineages have been studied at cellular resolution in multiple organs that turn over rapidly. However, many epithelia, including those of the lung, liver, pancreas, and prostate, turn over slowly and may be regulated differently. We investigated the mouse tracheal epithelial lineage at homeostasis by using long-term clonal analysis and mathematical modeling. This pseudostratified epithelium contains basal cells and secretory and multiciliated luminal cells. Our analysis revealed that basal cells are heterogeneous, comprising approximately equal numbers of multipotent stem cells and committed precursors, which persist in the basal layer for 11 days before differentiating to luminal fate. We confirmed the molecular and functional differences within the basal population by using single-cell qRT-PCR and further lineage labeling. Additionally, we show that self-renewal of short-lived secretory cells is a feature of homeostasis. We have thus revealed early luminal commitment of cells that are morphologically indistinguishable from stem cells. PMID:26119728

  9. ATG12–ATG3 connects basal autophagy and late endosome function

    PubMed Central

    Murrow, Lyndsay; Debnath, Jayanta

    2015-01-01

    In addition to supporting cell survival in response to starvation or stress, autophagy promotes basal protein and organelle turnover. Compared to our understanding of stress-induced autophagy, little is known about how basal autophagy is regulated and how its activity is coordinated with other cellular processes. We recently identified a novel interaction between the ATG12–ATG3 conjugate and the ESCRT-associated protein PDCD6IP/Alix that promotes basal autophagy and endolysosomal trafficking. Moreover, ATG12–ATG3 is required for diverse PDCD6IP-mediated functions including late endosome distribution, exosome secretion, and viral budding. Our results highlight the importance of late endosomes for basal autophagic flux and reveal distinct roles for the core autophagy proteins ATG12 and ATG3 in controlling late endosome function. PMID:25998418

  10. Cytokine effects on the basal ganglia and dopamine function: the subcortical source of inflammatory malaise.

    PubMed

    Felger, Jennifer C; Miller, Andrew H

    2012-08-01

    Data suggest that cytokines released during the inflammatory response target subcortical structures including the basal ganglia as well as dopamine function to acutely induce behavioral changes that support fighting infection and wound healing. However, chronic inflammation and exposure to inflammatory cytokines appears to lead to persisting alterations in the basal ganglia and dopamine function reflected by anhedonia, fatigue, and psychomotor slowing. Moreover, reduced neural responses to hedonic reward, decreased dopamine metabolites in the cerebrospinal fluid and increased presynaptic dopamine uptake and decreased turnover have been described. This multiplicity of changes in the basal ganglia and dopamine function suggest fundamental effects of inflammatory cytokines on dopamine synthesis, packaging, release and/or reuptake, which may sabotage and circumvent the efficacy of current treatment approaches. Thus, examination of the mechanisms by which cytokines alter the basal ganglia and dopamine function will yield novel insights into the treatment of cytokine-induced behavioral changes and inflammatory malaise. PMID:23000204

  11. Dual SMAD Signaling Inhibition Enables Long-Term Expansion of Diverse Epithelial Basal Cells.

    PubMed

    Mou, Hongmei; Vinarsky, Vladimir; Tata, Purushothama Rao; Brazauskas, Karissa; Choi, Soon H; Crooke, Adrianne K; Zhang, Bing; Solomon, George M; Turner, Brett; Bihler, Hermann; Harrington, Jan; Lapey, Allen; Channick, Colleen; Keyes, Colleen; Freund, Adam; Artandi, Steven; Mense, Martin; Rowe, Steven; Engelhardt, John F; Hsu, Ya-Chieh; Rajagopal, Jayaraj

    2016-08-01

    Functional modeling of many adult epithelia is limited by the difficulty in maintaining relevant stem cell populations in culture. Here, we show that dual inhibition of SMAD signaling pathways enables robust expansion of primary epithelial basal cell populations. We find that TGFβ/BMP/SMAD pathway signaling is strongly activated in luminal and suprabasal cells of several epithelia, but suppressed in p63+ basal cells. In airway epithelium, SMAD signaling promotes differentiation, and its inhibition leads to stem cell hyperplasia. Using dual SMAD signaling inhibition in a feeder-free culture system, we have been able to expand airway basal stem cells from multiple species. Expanded cells can produce functional airway epithelium physiologically responsive to clinically relevant drugs, such as CFTR modulators. This approach is effective for the clonal expansion of single human cells and for basal cell populations from epithelial tissues from all three germ layers and therefore may be broadly applicable for modeling of epithelia. PMID:27320041

  12. Basal foot MTOC organizes pillar MTs required for coordination of beating cilia

    PubMed Central

    Clare, Daniel K.; Magescas, Jérémy; Piolot, Tristan; Dumoux, Maud; Vesque, Christine; Pichard, Evelyne; Dang, Tien; Duvauchelle, Boris; Poirier, Françoise; Delacour, Delphine

    2016-01-01

    Coordination of ciliary beating is essential to ensure mucus clearance in the airway tract. The orientation and synchronization of ciliary motion responds in part to the organization of the underlying cytoskeletal networks. Using electron tomography on mouse trachea, we show that basal bodies are collectively hooked at the cortex by a regular microtubule array composed of 4-5 microtubules. Removal of Galectin-3, one of basal body components, provokes misrecruitment of γ-tubulin, disorganization of this microtubule framework emanating from the basal foot cap, together with loss of basal body alignment and cilium orientation, defects in cilium organization and reduced fluid flow in the tracheal lumen. We conclude that Galectin-3 plays a crucial role in the maintenance of the microtubule organizing center of the cilium and the “pillar” microtubules, and that this network is instrumental for the coordinated orientation and stabilization of motile cilia. PMID:25215410

  13. Cytokine Effects on the Basal Ganglia and Dopamine Function: the Subcortical Source of Inflammatory Malaise

    PubMed Central

    Felger, Jennifer C.; Miller, Andrew H.

    2012-01-01

    Data suggest that cytokines released during the inflammatory response target subcortical structures including the basal ganglia as well as dopamine function to acutely induce behavioral changes that support fighting infection and wound healing. However, chronic inflammation and exposure to inflammatory cytokines appears to lead to persisting alterations in the basal ganglia and dopamine function reflected by anhedonia, fatigue, and psychomotor slowing. Moreover, reduced neural responses to hedonic reward, decreased dopamine metabolites in the cerebrospinal fluid and increased presynaptic dopamine uptake and decreased turnover have been described. This multiplicity of changes in the basal ganglia and dopamine function suggest fundamental effects of inflammatory cytokines on dopamine synthesis, packaging, release and/or reuptake, which may sabotage and circumvent the efficacy of current treatment approaches. Thus, examination of the mechanisms by which cytokines alter the basal ganglia and dopamine function will yield novel insights into the treatment of cytokine-induced behavioral changes and inflammatory malaise. PMID:23000204

  14. Basal Cell Carcinoma: A Comprehensive Review of Existing and Emerging Nonsurgical Therapies.

    PubMed

    Lanoue, Julien; Goldenberg, Gary

    2016-05-01

    Basal cell carcinoma is the most commonly occurring cancer in the world and overall incidence is still on the rise. While typically a slow-growing tumor for which metastases is rare, basal cell carcinoma can be locally destructive and disfiguring. Given the vast prevalence of this disease, there is a significant overall burden on patient well-being and quality of life. The current mainstay of basal cell carcinoma treatment involves surgical modalities, such as electrodessication and curettage, excision, cryosurgery, and Mohs micrographic surgery. Such methods are typically reserved for localized basal cell carcinoma and offer high five-year cure rates, but come with the risk of functional impairment, disfigurement, and scarring. Here, the authors review the evidence and indications for nonsurgical treatment modalities in cases where surgery is impractical, contraindicated, or simply not desired by the patient. PMID:27386043

  15. Disturbed basal ice seen in radio echo images coincide with zones of big interlocking ice crystals.

    NASA Astrophysics Data System (ADS)

    Dahl-Jensen, Dorthe; Gogineni, Sivaprasad; Panton, Christian

    2014-05-01

    Improvement of the depth sounding radio echo sounding (RES) over Antarctica and Greenland Ice Sheet has made it possible to map the near basal layers that have not been 'seen' earlier due to the very high demand of attenuation needed to reach through more than 3000m of ice. The RES internal reflectors show that the near basal ice at many locations has disturbed layering. At the locations where ice cores reach the bedrock both in Greenland and Antarctica studies of the ice crystal size and orientation show that the near basal ice has big and interlocking ice crystals which suggests the ice is not actively deforming. These observations challenge the often used constitutive equations like Glens flow law in ice sheet modelling. A discussion of the impact of the RES findings on ice sheet modeling and the quest to find the oldest ice in Antarctic based on the anisotropy of the basal ice will follow.

  16. Basal Ganglia Subcircuits Distinctively Encode the Parsing and Concatenation of Action Sequences

    PubMed Central

    Jin, Xin; Tecuapetla, Fatuel; Costa, Rui M

    2014-01-01

    Chunking allows the brain to efficiently organize memories and actions. Although basal ganglia circuits have been implicated in action chunking, little is known about how individual elements are concatenated into a behavioral sequence at the neural level. Using a task where mice learn rapid action sequences, we uncovered neuronal activity encoding entire sequences as single actions in basal ganglia circuits. Besides start/stop activity signaling sequence parsing, we found neurons displaying inhibited or sustained activity throughout the execution of an entire sequence. This sustained activity covaried with the rate of execution of individual sequence elements, consistent with motor concatenation. Direct and indirect pathways of basal ganglia were concomitantly active during sequence initiation, but behaved differently during sequence performance, revealing a more complex functional organization of these circuits than previously postulated. These results have important implications for understanding the functional organization of basal ganglia during the learning and execution of action sequences. PMID:24464039

  17. Basal ganglia dysfunction in idiopathic REM sleep behaviour disorder parallels that in early Parkinson's disease.

    PubMed

    Rolinski, Michal; Griffanti, Ludovica; Piccini, Paola; Roussakis, Andreas A; Szewczyk-Krolikowski, Konrad; Menke, Ricarda A; Quinnell, Timothy; Zaiwalla, Zenobia; Klein, Johannes C; Mackay, Clare E; Hu, Michele T M

    2016-08-01

    SEE POSTUMA DOI101093/AWW131 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Resting state functional magnetic resonance imaging dysfunction within the basal ganglia network is a feature of early Parkinson's disease and may be a diagnostic biomarker of basal ganglia dysfunction. Currently, it is unclear whether these changes are present in so-called idiopathic rapid eye movement sleep behaviour disorder, a condition associated with a high rate of future conversion to Parkinson's disease. In this study, we explore the utility of resting state functional magnetic resonance imaging to detect basal ganglia network dysfunction in rapid eye movement sleep behaviour disorder. We compare these data to a set of healthy control subjects, and to a set of patients with established early Parkinson's disease. Furthermore, we explore the relationship between resting state functional magnetic resonance imaging basal ganglia network dysfunction and loss of dopaminergic neurons assessed with dopamine transporter single photon emission computerized tomography, and perform morphometric analyses to assess grey matter loss. Twenty-six patients with polysomnographically-established rapid eye movement sleep behaviour disorder, 48 patients with Parkinson's disease and 23 healthy control subjects were included in this study. Resting state networks were isolated from task-free functional magnetic resonance imaging data using dual regression with a template derived from a separate cohort of 80 elderly healthy control participants. Resting state functional magnetic resonance imaging parameter estimates were extracted from the study subjects in the basal ganglia network. In addition, eight patients with rapid eye movement sleep behaviour disorder, 10 with Parkinson's disease and 10 control subjects received (123)I-ioflupane single photon emission computerized tomography. We tested for reduction of basal ganglia network connectivity, and for loss of tracer uptake in rapid eye movement sleep

  18. Actor-critic models of the basal ganglia: new anatomical and computational perspectives.

    PubMed

    Joel, Daphna; Niv, Yael; Ruppin, Eytan

    2002-01-01

    A large number of computational models of information processing in the basal ganglia have been developed in recent years. Prominent in these are actor-critic models of basal ganglia functioning, which build on the strong resemblance between dopamine neuron activity and the temporal difference prediction error signal in the critic, and between dopamine-dependent long-term synaptic plasticity in the striatum and learning guided by a prediction error signal in the actor. We selectively review several actor-critic models of the basal ganglia with an emphasis on two important aspects: the way in which models of the critic reproduce the temporal dynamics of dopamine firing, and the extent to which models of the actor take into account known basal ganglia anatomy and physiology. To complement the efforts to relate basal ganglia mechanisms to reinforcement learning (RL), we introduce an alternative approach to modeling a critic network, which uses Evolutionary Computation techniques to 'evolve' an optimal RL mechanism, and relate the evolved mechanism to the basic model of the critic. We conclude our discussion of models of the critic by a critical discussion of the anatomical plausibility of implementations of a critic in basal ganglia circuitry, and conclude that such implementations build on assumptions that are inconsistent with the known anatomy of the basal ganglia. We return to the actor component of the actor-critic model, which is usually modeled at the striatal level with very little detail. We describe an alternative model of the basal ganglia which takes into account several important, and previously neglected, anatomical and physiological characteristics of basal ganglia-thalamocortical connectivity and suggests that the basal ganglia performs reinforcement-biased dimensionality reduction of cortical inputs. We further suggest that since such selective encoding may bias the representation at the level of the frontal cortex towards the selection of rewarded

  19. A comprehensive interpretation of the NEEM basal ice build-up using a multi parametric approach

    NASA Astrophysics Data System (ADS)

    Goossens, Thomas; Sapart, Celia Julia; Popp, Trevor; El Amri, Saïda; Tison, Jean-louis

    2015-04-01

    Basal ice is a common expression to describe debris-laden ice layers found close to the ice-bedrock interface under glaciers and ice sheets. The study of basal ice properties provides us with the unique opportunity of improving our understanding of subglacial environments and processes and refine ice sheet behaviour modelling. Here, we present and discuss the results of water stable isotopes (δ18O and δD), ice fabrics, debris weight and gas content of the basal part of the NEEM (North Eemian Ice Drilling Program) ice core. Below 2533.85 m deep, almost 10 m of basal debris-rich material were retrieved from the borehole. The situation at NEEM is different from the previously well-documented GRIP core where the basal ice corresponds to pre ice sheet ice overridden by the growing ice sheet. At NEEM, the basal debris-rich material presents δ18O values from -39.89 to -34.36 permil within the range of the above last 300 m of meteoric ice from -44.86 to -30.59 permil. The sequence is however composed of an alternation of three visually contrasting types of ice : clear ice with specks of particulate inclusions, stratified debris-rich layers, and ice containing dispersed debris. Using water stable isotopes (δ18O and δ D) signatures, each of these ice types are discriminated and clues are given for their conditions of formation and transformation processes. The proposed interpretation is then refined in the light of the other available parameters. While clear basal ice with specks corresponds to altered meteoric glacial ice, stratified debris-rich layer and ice containing dispersed debris present a melting/refreezing signature, somewhat blurred by mixing processes. Based on the identified origins of the different ice types, the present study proposes a first interpretative framework for the build-up of the NEEM basal ice sequence.

  20. The basal ganglia within a cognitive system in birds and mammals.

    PubMed

    Petkov, Christopher I; Jarvis, Erich D

    2014-12-01

    The primate basal ganglia are fundamental to Ackermann et al.'s proposal. However, primates and rodents are models for human cognitive functions involving basal ganglia circuits, and links between striatal function and vocal communication come from songbirds. We suggest that the proposal is better integrated in cognitive and/or motor theories on spoken language origins and with more analogous nonhuman animal models. PMID:25514958