Re-examination of the Effects of Food Abundance on Jaw Plasticity in Purple Sea Urchins

Morphological plasticity is a critical mechanism that animals use to cope with variations in resource availability. During periods of food scarcity, sea urchins demonstrate an increase in jaw length relative to test diameter. This trait is thought to be reversible and adaptive by yielding an increase in feeding efficiency. We directly test the hypotheses that (1) there are reversible shifts in jaw length to test diameter ratios with food abundance in individual urchins, and (2) these shifts alter feeding efficiency. Purple sea urchins, Strongylocentrotus purpuratus, were collected and placed in either high or low food treatments for 3 months, after which treatments were switched for two additional months between February and September, 2015 in La Jolla, CA (32.8674°N, 117.2530°W). Measurements of jaw length to test diameter ratios were significantly higher in low compared to high food urchins, but this was due to test growth in the high food treatments. Ratios of low food urchins did not change following a switch to high food conditions, indicating that this trait is not reversible within the time frame of this study. Relatively longer jaws were also not correlated with increased feeding efficiency. We argue that jaw length plasticity is not adaptive and is simply a consequence of exposure to high food availability, as both jaw and test growth halt when food is scarce

A molecular method to quantify sex-specific consumption of Chinook salmon (Oncorhynchus tshawytscha) by Pacific harbor seals (Phoca vitulina richardii) using scat

Sex-biased predation may potentially skew sex ratios in adult populations, which may affect reproduction. Sex-biased predation by pinnipeds is of particular interest as it may impact fish populations of conservation and commercial interest such as salmon. However, sex-biased predation is difficult to measure in the wild and this is particularly true for marine mammals, since predation events in open water are often hidden from direct observation. Molecular scatology (genetic analyses of scat) has been used to non-invasively determine the proportion of prey items consumed in the diet, and it may be possible to determine sex-specific consumption of prey items using a similar approach. In this study, I develop a molecular method to measure the proportions of male and female Chinook salmon (Oncorhynchus tshawytscha) consumed by harbor seals (Phoca vitulina richardii) employing scat. By using QPCR, I established that the proportions of male and female Chinook DNA could be determined in a controlled mixed sample by measuring a y-linked marker, GHp-Y, in the sample in relation to a male control sample. I then applied the assay to harbor seal scat samples from haul-outs in the Strait of Georgia, Canada. Although the assay amplified in 83% of scat samples, 30% of scat samples quantified had an estimated male proportion \u3e 1. The lack of robustness of the assay might have been a result of contaminants in scat DNA extractions, which differentially impacted target genes. Lastly, using whole body tissue mixtures of males and females, I constructed a calibration curve to relate the DNA measurements of the assay to biomass proportions. The calibration curve was skewed by high male DNA density (presumably due to differences in gonad mass between sexes) precluding my ability to infer sex-specific consumption. Chinook populations return to rivers at different stages of reproductive development, and the tissue DNA density bias observed in this study may only apply to certain prey populations in the field. Despite the DNA density male bias, the median estimated male proportion in scat samples was 0.31, which suggests that harbor seals are eating low amounts of male salmon and may have a bias towards females. However, further development of this approach is needed to make strong inferences about sex-specific consumption

SATL model lesson for teaching effect of temperature on rate of reaction

Physical Chemistry is an experimental science based upon theories supported by mathematical input. It is therefore crucial that one who teaches Physical Chemistry should give a wholesome knowledge about any issue relating to this vital discipline in chemistry. To achieve this end, a systematic approach to teaching and learning method is the most appropriate teaching method [1-2]. It helps to ingrain knowledge so that illustrations of different parameters  through systematic diagrams are helpful in in-depth transformation of  knowledge relating to any concept. [AJCE 4(2), Special Issue, May 2014

SATL Based Lesson for Teaching Grignard Reagents in Synthetic Organic Chemistry

Synthesizing new products from raw materials has been very popular aspects of research in organic chemistry. Traditionally, Grignard reagent has been very vital component of such synthetic procedures. Hence learning of various issues concerning with applications of Grignard reactions in synthetic organic chemistry is vital for enhancing the students creative capability. In this paper we will illustrate the uses of SATL methodology, which is recently getting popular [1- 3], in an SATL-based model lesson concerning teaching and learning of synthetic organic reactions related to Grignard reagents

The Stress Distribution on the Zygapophyseal Joint of Lumbar Vertebra by ANSYS Program

Zygapophyseal joints (or facet joints), are a plane synovial joint which located between the articular facet processes of the vertebral arch which is freely guided movable joints. Ten dried vertebrae were used for the lumbar region and taking (L4) as a sample to reveal stress pathways across the joints by using ANSYS program under different loading conditions which used Finite Elements Analysis model. Results obtained from the ANSYS program are important in understanding the boundary conditions for load analysis and the points of stress concentration which explained from the anatomical point of view and linked to muscle and ligament attachments. This model used as a computational tool to joint biomechanics and to prosthetic implant analysis

Evaluation of a method for fusing LIDAR data and multispectral images for building detection

In this paper, we describe the evaluation of a method for building detection by the Dempster-Shafer fusion of LIDAR data and multispectral images. For that purpose, ground truth was digitised for two test sites with quite different characteristics. Using these data sets, the heuristic model for the probability mass assignments of the method is validated, and rules for the tuning of the parameters of this model are discussed. Further we evaluate the contributions of the individual cues used in the classification process to the quality of the classification results. Our results show the degree to which the overall correctness of the results can be improved by fusing LIDAR data with multispectral images

Aquatic fauna and flora surveys at the Lennox Weir, Busselton

Water Corporation proposes to undertake infrastructure works on the Lennox Weir, near Busselton, Western Australia. Due to the potential impact on aquatic fauna and flora associated with the proposed works, the Water Corporation engaged the Harry Butler Institute (Murdoch University) to carry out a desktop review and field survey for flora and fauna upstream and downstream of the structure. The study aimed to provide an assessment of the likely impacts of the proposed works on prevailing native species, and develop recommendations to mitigate any potential identified impacts. A desktop assessment of the fauna and flora communities around Lennox Weir was initially conducted. Subsequently, standardised surveys were conducted for flora and fauna at Lennox Weir in August 2019, again in October 2019 for flora, and finally in January (into early February) 2020 for flora and fauna. The proposed replacement or removal of the Lennox Weir was found to have a moderate to high risk of localised impacts on freshwater fishes upstream; based on the four storm surge scenarios modelled by GHD (2018a). Contrary to recent impact assessment by GHD (2018b), high abundances of native fishes were found to be present upstream of the weir in summer, which could be impacted by sudden increases in salinity predicted by the storm surge modelling. The upstream spatial extent of this impact would depend on the storm surge scenario. However, under all scenarios freshwater fishes are likely to be impacted (including potential high levels of mortality) in zone 2 (from the weir to 500m upstream) and a proportion of zone 3 (between 500‐ 1100m upstream). However, while the known acute salinity tolerances of resident native fishes would be exceeded in those sections, the behavioural responses of the fishes may help to partially or totally) mitigate the impacts. This could include moving upstream away from the incoming saline water, or more likely, utilising a freshwater lens that may be present. However, the hydrological modelling by GHD (2018a) did not consider or model the potential for a freshwater surface layer to form. Additional modelling would be required to better predict whether these factors could occur to mitigate the impacts on freshwater fishes. The assessment also revealed that the Threatened (EPBC Act 1999) Carter’s Freshwater Mussel Westralunio carteri was present in the Lennox River from just upstream of the weir to at least the Vasse‐Yallingup Siding Rd. However, its relative abundance increased significantly with distance upstream of the weir and the lowest abundances were found in zones 2 and 3; the sites predicted to be most affected by increased salinity under the modelled storm surge scenarios. As concluded by the previous impact assessment (GHD 2018b), the risk to the species of the increase in salinity would be high to moderate in zones 2 and 3 with residual salinity after 24 hours under all four storm surge scenarios projected to exceed its known tolerances in zone 2 and a proportion of zone 3. However, there remains uncertainty of this impact owing to the fact that modelling of residual salinity was only undertaken for a 24 hour period. Previous acute salinity trials of the species revealed the initial deaths occurred after 10 days at 8 mg/l, highest salinity level tested. The impact on the species in terms of mortality would therefore likely depend on the longer‐term residual salinity levels following storm surges. The impact on the South‐west Snake Neck Turtle Chelodina colliei upstream of the Lennox Weir was assessed as low in the current study. While there may be a short‐term decline in abundances of salt‐intolerant freshwater fishes and invertebrates associated with the modelled storm surges, there were high abundances of alternative prey items present particularly the Blue‐spot Goby Pseodogobius olorum and South‐west Glass Shrimp Palaemon australis. While the Smooth Marron Cherax cainii was not detected during the current sampling in the impacted reach (only visually observed upstream at the Vasse‐Yallingup Siding Rd), additional anecdotal information from the landholder suggested they may be present in low abundances within zone 3. If present, those individuals would have a high risk of impact under all scenarios and would likely walk out of the river to avoid the salinity. The Lennox Weir survey area occurs within a Conservation Category Wetland area. Upstream and downstream vegetation differed in terms of community structure and condition. The upstream vegetation is an example of very old remnant riparian vegetation and included poorly represented community types. The vegetation provides habitat for the Critically Endangered Western Ringtail Possum, with extensive scat noted throughout the survey area. The P4 species Eucalyptus rudis subsp. cratyantha occurs in riparian vegetation upstream and downstream and on adjacent land north‐east of the weir. Changes to the salinity regime associated with altering the function of the weir are likely to impact this vegetation

Influence of dietary starch contents on milk composition of Friesian cows in early lactation

The aim of this research was to evaluate the effect of the modification of diet starch content on milk composition and onits nitrogen and mineral fractions. Ten Italian Friesian primiparous cows were randomly assigned to two groups and feda basal total mixed ration, (BSD, basal starch diet, 24.9% starch/DM) until 42 days in milking (DIM). At 43 DIM, 5 animals(control group, CTR) continued to receive the same ration and the remaining 5 cows (experimental group, EXP)were fed a low starch diet (LSD, 21.0% starch/DM) until 65 DIM, followed by a high starch diet (HSD, 28.3% starch/DM)66 to 85 DIM. From 86 DIM until 94 DIM, cows of the EXP group returned to the BSD. Milk samples were collected at 37,50, 60, 70, 80, 94 DIM. Starch intake was lower for EXP at DIM 50, 60 and higher at 70 and 80 DIM (P < 0.01). Milkyield and fat corrected milk (FCM) did not vary between groups and times of sampling, but HSD caused a significant (P< 0.05) reduction of milk fat in the EXP animals. NPN and MUN contents were affected by dietary treatments at 80 DIM(P < 0.05), being higher in CTR and lower in EXP group in comparison to their basal values (37 DIM). The αs1-caseinpercentages at 80 and 94 DIM increased in the EXP but not in the CTR group, and a marked decrease of αs2-casein percentagefor the EXP group at 94 DIM was observed (P < 0.05). Milk sodium content decreased at 80 and 94 DIM and thesodium to potassium ratio was reduced after the return to the basal diet in the EXP group (94 DIM), indicating that dietarystarch variations can be involved in the control of epithelium integrity of mammary gland in early lactation

Association between Psychosocial Factors, Quality of Life and Atrial Fibrillation

Background: Atrial fibrillation (AF) is associated with cognitive and psychosocial comorbidities, and poorer quality of life (QOL). In this study, we aimed to study the association between cognition, psychosocial status and QOL at baseline and AF recurrence. Methods: We enrolled 222 symptomatic AF patients (64±10.0 years, 36% women) treated with a rhythm-control strategy. We performed cognitive, psychosocial, and QOL assessments using Montreal cognitive assessment (MOCA, cognitive impairment Results: A total of 123 (55%) participants experienced an AF recurrence over the 6-month follow-up period. Participants with an AF recurrence had higher rates of depression (31% vs.14%, p=0.022) and lower QOL (62±24 vs. 72±21, p=0.003) at baseline than did participants free from recurrence. In multivariable logistic regression models, lower baseline QOL, but not depression, anxiety, or cognition, was associated with a significantly higher odds of AF recurrence event (Odds Ratio: 0.98, CI 0.97-0.99). Conclusion: Lower AF-related QOL is associated with higher odds of AF recurrence over 6 months among symptomatic AF patients treated with rhythm control. Patient-reported variables have not previously been considered as risk factors for disease progression or prognosis. Our data suggests QOL may serve as a useful tool to aid clinicians in the management of AF patients