Provision of ecosystem services by human-made structures in a highly impacted estuary

Water filtration is one of the most important ecosystem services provided by sessile organisms in coastal ecosystems. As a consequence of increased coastal development, human-made shoreline structures (e.g., docks and bulkheads) are now common, providing extensive surface area for colonization by filter feeders. We estimate that in a highly urbanized sub-tropical estuary, water filtration capacity supported by filter feeding assemblages on dock pilings accounts for 11.7 million liters of water h−1, or ~30% of the filtration provided by all natural oyster reef throughout the estuary. Assemblage composition, and thus filtration capacity, varied as a function of piling type, suggesting that the choice of building material has critical implications for ecosystem function. A more thorough depiction of the function of coastal ecosystems necessitates quantification of the extensive ecosystem services associated with human-made structures

Moderate carbohydrate, moderate protein weight loss diet reduces cardiovascular disease risk compared to high carbohydrate, low protein diet in obese adults: A randomized clinical trial

<p>Abstract</p> <p>Background</p> <p>To evaluate the metabolic effects of two weight loss diets differing in macronutrient composition on features of dyslipidemia and post-prandial insulin (INS) response to a meal challenge in overweight/obese individuals.</p> <p>Methods</p> <p>This study was a parallel-arm randomized 4 mo weight loss trial. Adults (n = 50, 47 ± 7 y) matched on BMI (33.6 ± 0.6 kg/m², <it>P </it>= 0.79) consumed energy restricted diets (deficit ~500 kcal/d): PRO (1.6 g.kg^-1.d^-1protein and < 170 g/d carbohydrate) or CHO (0.8 g.kg^-1.d^-1protein and > 220 g/d carbohydrate) for 4 mos. Meal challenges of respective diets were utilized for determination of blood lipids and post-prandial INS and glucose response at the beginning and end of the study.</p> <p>Results</p> <p>There was a trend for PRO to lose more weight (-9.1% vs. -7.3%, <it>P </it>= 0.07) with a significant reduction in percent fat mass compared to CHO (-8.7% vs. -5.7%; <it>P </it>= 0.03). PRO also favored reductions in triacylglycerol (-34% vs. -14%; <it>P </it>< 0.05) and increases in HDL-C (+5% vs. -3%; <it>P </it>= 0.05); however, CHO favored reduction in LDL-C (-7% vs. +2.5%; <it>P </it>< 0.05). INS responses to the meal challenge were improved in PRO compared to CHO (<it>P </it>< 0.05) at both 1 hr (-34.3% vs. -1.0%) and 2 hr (-9.2% vs. +46.2%), an effect that remained significant after controlling for weight or fat loss (both <it>P </it>< 0.05).</p> <p>Conclusion</p> <p>A weight loss diet with moderate carbohydrate, moderate protein results in more favorable changes in body composition, dyslipidemia, and post-prandial INS response compared to a high carbohydrate, low protein diet suggesting an additional benefit beyond weight management to include augmented risk reduction for metabolic disease.</p

How Does the Addition of Gel at the Time of Vaccination Affect Overall Nursery Pig Performance?

Swine industry feed suppliers are continually striving to create techniques and tools to reduce the additive stressors imposed on the weanling piglet, to increase advantageous behaviors (feeding and drinking) and to reduce aggrieve interactions. In addition to social reorganization, pigs are often vaccinated during the nursery phase to reduce the impact of potentially harmful diseases. It has been noted by swine practitioners that at the time of vaccination many pigs lie down, rest more and reduce the amount of feed consumption over the vaccination period. One product on the market is a gel-based feed that is designed to ease the transition from a liquid diet (sow\u27s milk) to dry ration. This gel-based feed contains high quality ingredients; it is highly palatable and provides the young pig with both a feed component and a water component thereby influencing feed consumption and intestinal health. The gel can be used in addition to a standard weaned pig solid ration. Although, often recommended to be used at the time of weaning, the possibilities of implementing the gel around the time of vaccination is a novel concept that might impact the individual pig’s overall performance. The objectives of this study were to determine if the addition of gel at the time of vaccination provided benefits to the nursery pigs’ performance

A high protein moderate carbohydrate diet fed at discrete meals reduces early progression of N-methyl-N-nitrosourea-induced breast tumorigenesis in rats

Breast cancer is the most prevalent cancer in American women. Dietary factors are thought to have a strong influence on breast cancer incidence. This study utilized a meal-feeding protocol with female Sprague-Dawley rats to evaluate effects of two ratios of carbohydrate:protein on promotion and early progression of breast tissue carcinomas. Mammary tumors were induced by N-methyl-N-nitrosourea (MNU) at 52 d of age. Post-induction, animals were assigned to consume either a low protein high carbohydrate diet (LPHC; 15% and 60% of energy, respectively) or a high protein moderate carbohydrate diet (HPMC; 35% and 40% of energy, respectively) for 10 wk. Animals were fed 3 meals/day to mimic human absorption and metabolism patterns. The rate of palpable tumor incidence was reduced in HPMC relative to LPHC (12.9 ± 1.4%/wk vs. 18.2 ± 1.3%/wk). At 3 wk, post-prandial serum insulin was larger in the LPHC relative to HPMC (+136.4 ± 33.1 pmol/L vs. +38.1 ± 23.4 pmol/L), while at 10 wk there was a trend for post-prandial IGF-I to be increased in HPMC (P = 0.055). There were no differences in tumor latency, tumor surface area, or cumulative tumor mass between diet groups. The present study provides evidence that reducing the dietary carbohydrate:protein ratio attenuates the development of mammary tumors. These findings are consistent with reduced post-prandial insulin release potentially diminishing the proliferative environment required for breast cancer tumors to progress

Differences in Nursery Pigs’ Behavior on the Day of Vaccination

Swine industry feed suppliers are continually striving to develop techniques and tools to reduce the additive stressors imposed on the weanling piglet, to increase advantageous behaviors (feeding and drinking) and to reduce aggressive interactions. One product on the market designed to ease the transition from a liquid diet (sow\u27s milk) to a dry ration is a gel-based feed supplement that was incorporated in this trial as a means to positively affect feeding and drinking behaviors. The objectives of this study were to determine if there were differences in the nursery pigs’ behavior on the day of vaccination when provided a gel supplement. A total of 29 d crossbred pigs (5.94 kg) were housed in Double L® confinement nursery buildings. Four treatments were compared. No vaccine and no gel (control n = 4) defined as unvaccinated and without supplemental gel at days 8 to 10. No vaccine and gel (n = 4) defined as pigs that were provided supplemental gel at days 8 to 10 without vaccination. Vaccinated and no gel (n = 4) defined as pigs that were vaccinated but did not receive supplemental gel at days 8 to 10. Vaccinated and gel (n = 4) defined as pigs that were provided supplemental gel at days 8 to 10 and were vaccinated. The group of four pigs housed together in a pen was considered the experimental unit for data analysis. Definitions for the behaviors and postures recorded and summarized for the trial included the following: Active was defined as standing, this included any upright postures. Inactive posture was defined as sitting or lying postures (both lateral and sternal). Time at drinker was defined as when an individual pig’s mouth was around the water nipple. Time at feeding stations was defined as the time when the individual pig’s head was inside the creep (that contained gel) or the three hole feeder (dry pelleted feed). Nursery aged pigs were less active (P \u3c 0.05; Figure 1) and spent less time (P \u3c 0.05; Figure 2) at the feeding stations 1- h after receiving Mycoplasma hyopneumoniae vaccination, indicating a short term behavioral response to this stressor. These behavioral alterations continued for approximately 6- h (or 5:00 PM the vaccination day afternoon). After this time, all nursery pigs regardless of treatment engaged in the same behavioral repertoire. However, the behavioral repertoire of these nursery pigs were not different over the 3-d trial (previously published worked by Johnson et al., 2008) suggesting that the effects of this vaccination stressor and product were not long lasting

Prey naiveté to invasive lionfish Pterois volitans on Caribbean coral reefs

Native prey can be particularly vulnerable to consumption by exotic predators. Prey naiveté, the failure to recognize a novel predator due to lack of recent co-evolutionary history, likely facilitates the disproportionate impact that some exotic predators exert on prey populations. Lionfish Pterois volitans, exotic predators from the Pacific, have invaded coral reefs and other coastal habitats along the western Atlantic. Prey naiveté towards novel lionfish was tested in field experiments and with observations using closest approach distance as the anti-predator response. We quantified the distance of prey fishes to exotic lionfish in both the Atlantic and Pacific (invasive and native ranges of lionfish) as well as to native predators in the Atlantic. In the Atlantic, experiments indicated that Haemulon plumierii, prey of lionfish, generally display a closer approach distance to exotic than to native predators, and field observations of free-ranging fish revealed that at least 5 other species of small fishes (Halichoeres bivitattus, Halichoeres garnoti, Scarus taeniopterus, Stegastes leucostictus and Thalassoma bifasciatum) also might exhibit limited predatoravoidance behaviour towards invasive lionfish. We also found that 3 families of small fish (Labridae, Pomacentridae and Scaridae) maintained greater distances from lionfish in the Pacific compared with the Atlantic in both experimental and field observations. These results suggest prey naiveté to exotic lionfish by at least 8 species of fish (Abudefduf saxatilis, H. plumierii, H. bivitattus, H. garnoti, S. taeniopterus, Sparisoma aurofrenatum, S. leucostictus and T. bifasciatum) in the Atlantic, which could be contributing to the rapid expansion of this invasive species by enhancing its fitness and reproductive output through high predation efficiency

The Effect of Supplementing Dry Feed with a Nutritional Gel Product at the Time of Vaccination on Nursery Pig Maintenance Behaviors and Postures

Swine industry feed suppliers are continually striving to develop techniques and tools to reduce the additive stressors imposed on the weanling piglet, to increase advantageous behaviors (feeding and drinking) and to reduce aggressive interactions. One product on the market designed to ease the transition from a liquid diet (sow\u27s milk) to a dry ration is a gel-based feed supplement that was incorporated in this trial as a means to positively affect the aforementioned parameters. The trial was conducted in the spring of 2007. A total of 64 3-week old, crossbred pigs (4.2 kg) were received from a commercial farm and housed in Double L ® confinement nursery buildings. Four treatments were compared. Control groups (n = 4) were defined as unvaccinated and without supplemental gel at days 9 to 11. Treatment one (TRT 1 n = 4 groups) was provided supplemental gel at days 9 to 11 without vaccination. Treatment two (TRT 2; n = 4 groups) was vaccinated but did not receive supplemental gel at days 9 to 11. Treatment three (TRT 3; n = 4 groups) received supplemental gel at days 9 to 11 and were vaccinated. The group of four pigs housed together in a pen was considered the experimental unit for data analysis. Definitions for the behaviors and postures recorded and summarized for the trial included the following: Active was defined as standing, this included any upright postures. Inactive posture was defined as sitting or lying postures (both lateral and sternal). Time at drinker was defined as when an individual pig’s mouth was around the water nipple. Time at feeding stations was defined as the time when the individual pig’s head was inside the creep (that contained gel) or the three hole feeder (dry pelleted feed). There were no differences between treatments for active (P = 0.60), inactive (P = 0.99) or time at drinker (P = 0.37), respectively. There was a difference (P = 0.0085) between treatments for the percentage of time spent at the feeding stations with pigs receiving vaccine and no gel spending the least amount of time at the feeding stations compared to the other three treatment groups. Therefore, the availability of a gel product when pigs are vaccinated provided some benefit, as the time spent at the feeding station was higher compared to pigs that did not have access to the gel

The Case for Dynamic Models of Learners' Ontologies in Physics

In a series of well-known papers, Chi and Slotta (Chi, 1992; Chi & Slotta, 1993; Chi, Slotta & de Leeuw, 1994; Slotta, Chi & Joram, 1995; Chi, 2005; Slotta & Chi, 2006) have contended that a reason for students' difficulties in learning physics is that they think about concepts as things rather than as processes, and that there is a significant barrier between these two ontological categories. We contest this view, arguing that expert and novice reasoning often and productively traverses ontological categories. We cite examples from everyday, classroom, and professional contexts to illustrate this. We agree with Chi and Slotta that instruction should attend to learners' ontologies; but we find these ontologies are better understood as dynamic and context-dependent, rather than as static constraints. To promote one ontological description in physics instruction, as suggested by Slotta and Chi, could undermine novices' access to productive cognitive resources they bring to their studies and inhibit their transition to the dynamic ontological flexibility required of experts.Comment: The Journal of the Learning Sciences (In Press