Feeding behavior of the ctenophore Thalassocalyce inconstans : revision of anatomy of the order Thalassocalycida

© 2009 The Authors. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License. The definitive version was published in Marine Biology 156 (2009): 1049-1056, doi:10.1007/s00227-009-1149-6.Behavioral observations using a remotely operated vehicle (ROV) in the Gulf of California in March, 2003, provided insights into the vertical distribution, feeding and anatomy of the rare and delicate ctenophore Thalassocalyce inconstans. Additional archived ROV video records from the Monterey Bay Aquarium Research Institute of 288 sightings of T. inconstans and 2,437 individual observations of euphausiids in the Gulf of California and Monterey Canyon between 1989 and 2005 were examined to determine ctenophore and euphausiid prey depth distributions with respect to temperature and dissolved oxygen concentration [dO]. In the Gulf of California most ctenophores (96.9%) were above 350 m, the top of the oxygen minimum layer. In Monterey Canyon the ctenophores were more widely distributed throughout the water column, including the hypoxic zone, to depths as great as 3,500 m. Computer-aided behavioral analysis of two video records of the capture of euphausiids by T. inconstans showed that the ctenophore contracted its bell almost instantly (0.5 s), transforming its flattened, hemispherical resting shape into a closed bi-lobed globe in which seawater and prey were engulfed. Euphausiids entrapped within the globe displayed a previously undescribed escape response for krill (‘probing behavior’), in which they hovered and gently probed the inner surfaces of the globe with antennae without stimulating further contraction by the ctenophore. Such rapid bell contraction could be effected only by a peripheral sphincter muscle even though the presence of circumferential ring musculature was unknown for the Phylum Ctenophora. Thereafter, several live T. inconstans were collected by hand off Barbados and microscopic observations confirmed that assumption.Supported by the David and Lucile Packard Foundation and NOAA Grant #NA06OAR4600091

Origins of cattle on Chirikof Island, Alaska, elucidated from genome-wide SNP genotypes

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What orthopaedic surgery residents need to know about the hand and wrist?

<p>Abstract</p> <p>Background</p> <p>To develop a Core Curriculum for Orthopaedic Surgery; and to conduct a national survey to assess the importance of curriculum items as judged by orthopaedic surgeons with primary affiliation non-academic. Attention for this manuscript was focused on determining the importance of topics pertaining to adult hand and wrist reconstruction.</p> <p>Methods</p> <p>A 281-item questionnaire was developed and consisted of three sections: 1) Validated Musculoskeletal Core Curriculum; 2) Royal College of Physician and Surgeons of Canada (RCPSC) Specialty Objectives and; 3) A procedure list. A random group of 131 [out of 156] orthopaedic surgeons completed the questionnaire. Data were analyzed descriptively and quantitatively using histograms, a Modified Hotel ling's T²-statistic <abbrgrp><abbr bid="B1">1</abbr></abbrgrp> with p-value determined by a permutation test, and the Benjamini-Hochberg/Yekutieli procedure</p> <p>Results</p> <p>131/156 (84%) orthopaedic surgeons participated in this study. 27/32 items received an average mean score of at least 3.0/4.0 by all respondents thus suggesting that 84% of the items are either "probably important" or "important" to know by the end of residency (SD range 0.007–0.228). The Benjamini-Hochberg procedure demonstrated that for 80% of the 32 × 31/2 = 496 possible pairs of hand and wrist questions did not appear to demonstrate the same distribution of ratings given that one question was different from that of another question.</p> <p>Conclusion</p> <p>This study demonstrates with reliable statistical evidence, agreement on the importance of 27/32 items pertaining to hand and wrist reconstruction is included in a Core Curriculum for Orthopaedic Surgery. Residency training programs need ensure that educational opportunities focusing on the ability to perform with proficiency procedures pertaining to the hand and wrist is taught and evaluated in their respective programs.</p

Dental caries in Uruguayan adults and elders: findings from the first Uruguayan National Oral Health Survey

This study aimed to assess dental caries status and associated factors in Uruguayan adults and elders using data from the first Uruguayan National Oral Health Survey. Data were representative of the country as a whole. Socio-demographic information was collected with a closed questionnaire. Dental caries was assessed by clinical examination using the DMFT index. The final sample consisted of 769 participants. Mean DMFT was 15.20 and 24.12 for the 35-44 and 65-74-year age groups, respectively. Mean number of decayed teeth was 1.70 in adults and 0.66 in elders. Multivariate analyses showed higher prevalence of dental caries associated with age 65-74 years, low socioeconomic status, use of public dental services, presence of gingivitis; for decayed teeth, age 35-44 years, low socioeconomic status, use of public dental services, infrequent tooth brushing, need for oral health care, and presence of root caries showed higher severity. Uruguayan adults and elders from disadvantaged backgrounds concentrated a heavier burden of dental caries

Nodes of Ranvier and Paranodes in Chronic Acquired Neuropathies

Chronic acquired neuropathies of unknown origin are classified as chronic inflammatory demyelinating polyneuropathies (CIDP) and chronic idiopathic axonal polyneuropathies (CIAP). The diagnosis can be very difficult, although it has important therapeutic implications since CIDP can be improved by immunomodulating treatment. The aim of this study was to examine the possible abnormalities of nodal and paranodal regions in these two types of neuropathies. Longitudinal sections of superficial peroneal nerves were obtained from biopsy material from 12 patients with CIDP and 10 patients with CIAP and studied by immunofluorescence and in some cases electron microscopy. Electron microscopy revealed multiple alterations in the nodal and paranodal regions which predominated in Schwann cells in CIDP and in axons in CIAP. In CIDP paranodin/Caspr immunofluorescence was more widespread than in control nerves, extending along the axon in internodes where it appeared intense. Nodal channels Nav and KCNQ2 were less altered but were also detected in the internodes. In CIAP paranodes, paranodin labeling was irregular and/or decreased. To test the consequences of acquired primary Schwann cells alteration on axonal proteins, we used a mouse model based on induced deletion of the transcription factor Krox-20 gene. In the demyelinated sciatic nerves of these mice we observed alterations similar to those found in CIDP by immunofluorescence, and immunoblotting demonstrated increased levels of paranodin. Finally we examined whether the alterations in paranodin immunoreactivity could have a diagnosis value. In a sample of 16 biopsies, the study of paranodin immunofluorescence by blind evaluators led to correct diagnosis in 70±4% of the cases. This study characterizes for the first time the abnormalities of nodes of Ranvier in CIAP and CIDP, and the altered expression and distribution of nodal and paranodal proteins. Marked differences were observed between CIDP and CIAP and the alterations in paranodin immunofluorescence may be an interesting tool for their differential diagnosis

Acidogenic Potential of “Sugar-Free” Cough Drops

A patient presented with extensive marginal ditching around restorations recently placed during whole-mouth rehabilitation. The patient was not xerostomic and was otherwise normal except for the self-reported excessive use of “sugar-free” cough drops sweetened with sorbitol and Isomalt® (an equimolar mix of glucosyl-mannitol and glucosylsorbitol). This prompted an in vitro investigation to determine whether Streptococcus sobrinus 6715, a cariogenic streptococcus, could grow and produce acid in growth medium containing an aqueous extract of such “sugar-free” cough drops. The results indicate that S. sobrinus 6715 uses Isomalt® and sorbitol extensively, producing terminal culture pH as low as 4.2 when grown on medium with cough drop extract containing these sugars. This pH is sufficient to demineralize dental enamel. Patients should be cautioned against the chronic overuse of “sugar-free” cough drops and other “sugar-free” confections sweetened with a mixture of Isomalt® and sorbitol

Determinants of access to HIV testing and counselling services among female sex workers in sub-Saharan Africa: a systematic review

Quality appraisal tool. (DOCX 20 kb

Adipose-Derived Stem Cells Stimulate Regeneration of Peripheral Nerves: BDNF Secreted by These Cells Promotes Nerve Healing and Axon Growth De Novo

Transplantation of adipose-derived mesenchymal stem cells (ASCs) induces tissue regeneration by accelerating the growth of blood vessels and nerve. However, mechanisms by which they accelerate the growth of nerve fibers are only partially understood. We used transplantation of ASCs with subcutaneous matrigel implants (well-known in vivo model of angiogenesis) and model of mice limb reinnervation to check the influence of ASC on nerve growth. Here we show that ASCs stimulate the regeneration of nerves in innervated mice's limbs and induce axon growth in subcutaneous matrigel implants. To investigate the mechanism of this action we analyzed different properties of these cells and showed that they express numerous genes of neurotrophins and extracellular matrix proteins required for the nerve growth and myelination. Induction of neural differentiation of ASCs enhances production of brain-derived neurotrophic factor (BDNF) as well as ability of these cells to induce nerve fiber growth. BDNF neutralizing antibodies abrogated the stimulatory effects of ASCs on the growth of nerve sprouts. These data suggest that ASCs induce nerve repair and growth via BDNF production. This stimulatory effect can be further enhanced by culturing the cells in neural differentiation medium prior to transplantation

The early bee catches the flower - circadian rhythmicity influences learning performance in honey bees, Apis mellifera

Circadian rhythmicity plays an important role for many aspects of honey bees’ lives. However, the question whether it also affects learning and memory remained unanswered. To address this question, we studied the effect of circadian timing on olfactory learning and memory in honey bees Apis mellifera using the olfactory conditioning of the proboscis extension reflex paradigm. Bees were differentially conditioned to odours and tested for their odour learning at four different “Zeitgeber” time points. We show that learning behaviour is influenced by circadian timing. Honey bees perform best in the morning compared to the other times of day. Additionally, we found influences of the light condition bees were trained at on the olfactory learning. This circadian-mediated learning is independent from feeding times bees were entrained to, indicating an inherited and not acquired mechanism. We hypothesise that a co-evolutionary mechanism between the honey bee as a pollinator and plants might be the driving force for the evolution of the time-dependent learning abilities of bees