Effects of the terms associated with phi(zz) in free surface condition on the attitudes and resistance of different ships

One of approaches for numerical simulation of a ship moving in a still water is based on the composition of double-body flow and wavy flow solved by a boundary element method. There are several terms related to the second order derivative (ϕzz) of double-body flow velocity potential with respect to the vertical coordinate in the free surface conditions. Understanding of the effects of the terms is very limited so far. In many cases, they are just ignored even for ships with a high forward speed, particularly in the cases associated with multihull ships, for which no investigations on their effects have been found. This paper will present a study on the effects of the terms on the numerical prediction of the attitudes and resistance of different ships in various situations, including monohull, catamaran and trimaran with different parameters and at different Froude numbers. The results will demonstrate that the effects of the terms are significant in many cases and that considering this term may lead to the results similar to those obtained by fully nonlinear models at high Froude numbers

Iron, silicate, and light co-limitation of three Southern Ocean diatom species

The effect of combined iron, silicate, and light co-limitation was investigated in the three diatom species Actinocyclus sp. Ehrenberg, Chaetoceros dichaeta Ehrenberg, and Chaetoceros debilis Cleve, isolated from the Southern Ocean (SO). Growth of all species was co-limited by iron and silicate, reflected in a significant increase in the number of cell divisions compared to the control. Lowest relative Si uptake and drastic frustule malformation was found under iron and silicate co-limitation in C. dichaeta, while Si limitation in general caused cell elongation in both Chaetoceros species. Higher light intensities similar to SO surface conditions showed a negative impact on growth of C. dichaeta and Actinocyclus sp. and no effect on C. debilis. This is in contrast to the assumed light limitation of SO diatoms due to deep wind driven mixing. Our results suggest that growth and species composition of Southern Ocean diatoms is influenced by a sensitive interaction of the abiotic factors, iron, silicate, and light

Analysis of spatial relationships in three dimensions: tools for the study of nerve cell patterning

<p>Abstract</p> <p>Background</p> <p>Multiple technologies have been brought to bear on understanding the three-dimensional morphology of individual neurons and glia within the brain, but little progress has been made on understanding the rules controlling cellular patterning. We describe new matlab-based software tools, now available to the scientific community, permitting the calculation of spatial statistics associated with 3D point patterns. The analyses are largely derived from the Delaunay tessellation of the field, including the nearest neighbor and Voronoi domain analyses, and from the spatial autocorrelogram.</p> <p>Results</p> <p>Our tools enable the analysis of the spatial relationship between neurons within the central nervous system in 3D, and permit the modeling of these fields based on lattice-like simulations, and on simulations of minimal-distance spacing rules. Here we demonstrate the utility of our analysis methods to discriminate between two different simulated neuronal populations.</p> <p>Conclusion</p> <p>Together, these tools can be used to reveal the presence of nerve cell patterning and to model its foundation, in turn informing on the potential developmental mechanisms that govern its establishment. Furthermore, in conjunction with analyses of dendritic morphology, they can be used to determine the degree of dendritic coverage within a volume of tissue exhibited by mature nerve cells.</p

Presynaptic partner selection during retinal circuit reassembly varies with timing of neuronal regeneration in vivo

Whether neurons can restore their original connectivity patterns during circuit repair is unclear. Taking advantage of the regenerative capacity of zebrafish retina, we show here the remarkable specificity by which surviving neurons reassemble their connectivity upon regeneration of their major input. H3 horizontal cells (HCs) normally avoid red and green cones, and prefer ultraviolet over blue cones. Upon ablation of the major (ultraviolet) input, H3 HCs do not immediately increase connectivity with other cone types. Instead, H3 dendrites retract and re-extend to contact new ultraviolet cones. But, if regeneration is delayed or absent, blue-cone synaptogenesis increases and ectopic synapses are made with red and green cones. Thus, cues directing synapse specificity can be maintained following input loss, but only within a limited time period. Further, we postulate that signals from the major input that shape the H3 HC's wiring pattern during development persist to restrict miswiring after damage

Sleep loss drives acetylcholine- and somatostatin interneuron-mediated gating of hippocampal activity to inhibit memory consolidation

Sleep loss disrupts consolidation of hippocampus-dependent memory. To characterize effects of learning and sleep loss, we quantified activity-dependent phosphorylation of ribosomal protein S6 (pS6) across the dorsal hippocampus of mice. We find that pS6 is enhanced in dentate gyrus (DG) following single-trial contextual fear conditioning (CFC) but is reduced throughout the hippocampus after brief sleep deprivation (SD; which disrupts contextual fear memory [CFM] consolidation). To characterize neuronal populations affected by SD, we used translating ribosome affinity purification sequencing to identify cell type-specific transcripts on pS6 ribosomes (pS6-TRAP). Cell type-specific enrichment analysis revealed that SD selectively activated hippocampal somatostatin-expressing (Sst+) interneurons and cholinergic and orexinergic hippocampal inputs. To understand the functional consequences of SD-elevated Sst+ interneuron activity, we used pharmacogenetics to activate or inhibit hippocampal Sst+ interneurons or cholinergic input from the medial septum. The activation of either cell population was sufficient to disrupt sleep-dependent CFM consolidation by gating activity in granule cells. The inhibition of either cell population during sleep promoted CFM consolidation and increased S6 phosphorylation among DG granule cells, suggesting their disinhibition by these manipulations. The inhibition of either population across post-CFC SD was insufficient to fully rescue CFM deficits, suggesting that additional features of sleeping brain activity are required for consolidation. Together, our data suggest that state-dependent gating of DG activity may be mediated by cholinergic input and local Sst+ interneurons. This mechanism could act as a sleep loss-driven inhibitory gate on hippocampal information processing.</p

Perspective on Employment Opportunities of People with Disabilities in San Gabriel, La Union

For PWDs, employment is not only a way to gain income; it also gives a chance to showcase untapped skills, provide opportunities and allow social inclusion. However, PWDs still experience common patterns of discrimination and suffer high unemployment rates. In spite of several promotions worldwide, the employment rate is considerably lower for PWDs than for people without disabilities. This study sought to know the status of inclusion of PWDs in employment in San Gabriel, La Union, the opportunities present, and the interventions to address them. The descriptive qualitative design was utilized in this study. A semi-structured interview was conducted with the PWDs. Thematization was used to analyze the responses. Results revealed that the respondents face difficulties in finding a job before the pandemic because of the limited number of jobs available and became even more challenging during the pandemic due to imposed restrictions. Although they find it difficult because of limitations, results showed that they are not discriminated against in the workplace. Moreover, the available employment opportunities for PWDs are classified under blue-collar jobs. Additionally, respondents recommend giving attention to PWDs in order to address the employment opportunities through interventions. The researchers concluded that the status of inclusion of PWDs in employment is considerably low because of the limited jobs available. Similarly, work opportunities are also insufficient. Interventions to address the employment opportunities include facilitating programs and skills training for PWDs and opening simple job positions in the municipality or barangays

Inorganic carbon physiology underpins macroalgal responses to elevated CO2

Beneficial effects of CO2 on photosynthetic organisms will be a key driver of ecosystem change under ocean acidification. Predicting the responses of macroalgal species to ocean acidification is complex, but we demonstrate that the response of assemblages to elevated CO2 are correlated with inorganic carbon physiology. We assessed abundance patterns and a proxy for CO2:HCO3- use (\u3b413C values) of macroalgae along a gradient of CO2 at a volcanic seep, and examined how shifts in species abundance at other Mediterranean seeps are related to macroalgal inorganic carbon physiology. Five macroalgal species capable of using both HCO3- and CO2 had greater CO2 use as concentrations increased. These species (and one unable to use HCO3-) increased in abundance with elevated CO2 whereas obligate calcifying species, and non-calcareous macroalgae whose CO2 use did not increase consistently with concentration, declined in abundance. Physiological groupings provide a mechanistic understanding that will aid us in determining which species will benefit from ocean acidification and why

What are we measuring? A critique of range of motion methods currently in use for Dupuytren's disease and recommendations for practice

Background: Range of motion is the most frequently reported measure used in practice to evaluate outcomes. A goniometer is the most reliable tool to assess range of motion yet, the lack of consistency in reporting prevents comparison between studies. The aim of this study is to identify how range of motion is currently assessed and reported in Dupuytren’s disease literature. Following analysis recommendations for practice will be made to enable consistency in future studies for comparability. This paper highlights the variation in range of motion reporting in Dupuytren’s disease. Methods: A Participants, Intervention, Comparison, Outcomes and Study design format was used for the search strategy and search terms. Surgery, needle fasciotomy or collagenase injection for primary or recurrent Dupuytren’s disease in adults were included if outcomes were monitored using range of motion to record change. A literature search was performed in May 2013 using subject heading and free-text terms to also capture electronic publications ahead of print. In total 638 publications were identified and following screening 90 articles met the inclusion criteria. Data was extracted and entered onto a spreadsheet for analysis. A thematic analysis was carried out to establish any duplication, resulting in the final range of motion measures identified. Results: Range of motion measurement lacked clarity, with goniometry reportedly used in only 43 of the 90 studies, 16 stated the use of a range of motion protocol. A total of 24 different descriptors were identified describing range of motion in the 90 studies. While some studies reported active range of motion, others reported passive or were unclear. Eight of the 24 categories were identified through thematic analysis as possibly describing the same measure, ‘lack of joint extension’ and accounted for the most frequently used. Conclusions: Published studies lacked clarity in reporting range of motion, preventing data comparison and meta-analysis. Percentage change lacks context and without access to raw data, does not allow direct comparison of baseline characteristics. A clear description of what is being measured within each study was required. It is recommended that range of motion measuring and reporting for Dupuytren’s disease requires consistency to address issues that fall into 3 main categories:- Definition of terms Protocol statement Outcome reportin