Population genetics of native shellfish aquaculture species and potential genetic risks of cultivation

Native shellfish aquaculture has many benefits, but interbreeding of hatchery and wild populations may pose genetic risks to wild populations. The type and magnitude of these risks depends in part on the genetic population structure of native shellfish species. Early genetic studies on marine shellfish provided little evidence for such structure. However, recent population genetic studies provide higher resolution, make use of both neutral and non-neutral molecular markers, and suggest some marine shellfish can exhibit population structure and even local adaptation. Here, we present preliminary results on genetic differentiation among populations of Crassadoma gigantea (the purple-hinged rock scallop) and Parastichopus californicus (the giant California sea cucumber), two native species that are currently being developed for aquaculture production in Puget Sound. Data for both species demonstrate high levels of genetic diversity and indications for population structuring by geography. Additionally, data for P. californicus suggest a potential cryptic species. Results will be used in a genetic risk model to quantify risk under multiple management scenarios, which will provide decision support to resource managers and other stakeholders. Our study shows the importance of population structure for genetic risk assessment and the power of combining empirical data, computer modeling and end-user input

Metabolic recovery and compensatory shell growth of juvenile Pacific geoduck \u3cem\u3ePanopea generosa\u3c/em\u3e following short-term exposure to acidified seawater

While acute stressors can be detrimental, environmental stress conditioning can improve performance. To test the hypothesis that physiological status is altered by stress conditioning, we subjected juvenile Pacific geoduck, Panopea generosa, to repeated exposures of elevated pCO2 in a commercial hatchery setting followed by a period in ambient common garden. Respiration rate and shell length were measured for juvenile geoduck periodically throughout short-term repeated reciprocal exposure periods in ambient (~550 μatm) or elevated (~2400 μatm) pCO2 treatments and in common, ambient conditions, 5 months after exposure. Short-term exposure periods comprised an initial 10-day exposure followed by 14 days in ambient before a secondary 6-day reciprocal exposure. The initial exposure to elevated pCO2 significantly reduced respiration rate by 25% relative to ambient conditions, but no effect on shell growth was detected. Following 14 days in common garden, ambient conditions, reciprocal exposure to elevated or ambient pCO2 did not alter juvenile respiration rates, indicating ability for metabolic recovery under subsequent conditions. Shell growth was negatively affected during the reciprocal treatment in both exposure histories; however, clams exposed to the initial elevated pCO2 showed compensatory growth with 5.8% greater shell length (on average between the two secondary exposures) after 5 months in ambient conditions. Additionally, clams exposed to the secondary elevated pCO2 showed 52.4% increase in respiration rate after 5 months in ambient conditions. Early exposure to low pH appears to trigger carryover effects suggesting bioenergetic re-allocation facilitates growth compensation. Life stage-specific exposures to stress can determine when it may be especially detrimental, or advantageous, to apply stress conditioning for commercial production of this long-lived burrowing clam

Early anterior knee pain in male adolescent basketball players is related to body height and abnormal knee morphology.

To compare knee torque, range of motion, quality of movement, and morphology in dominant and nondominant legs of male adolescent basketball players with and without anterior knee pain and untrained peers.Cross-sectional.Sports performance laboratory.Male basketball players aged 14-15 years with and without anterior knee pain and healthy untrained subjects (n = 88).Basketball players were allocated to a symptomatic or asymptomatic group based on self-reported anterior knee pain. Associations between pain and body mass, height, passive range of motion, muscle peak torque, coactivation, neuromuscular control, proprioception, and ultrasound observations were investigated.The prevalence of pain did not differ significantly between sides. Of 176 knees inspected, 44 were painful, and 26 of these exhibited abnormalities in ultrasonography. Symptomatic players were 5.0 and 6.9 cm taller than asymptomatic players and controls, respectively (P < 0.05). In athletes with knee pain, the odds ratios of morphological abnormalities and greater height were increased by 8.6 and 5.0 times (P < 0.001).Knee pain prevalence in adolescent basketball players was not related to differences between sides but was higher in tall players. Knee pain was accompanied by morphological abnormalities detected with ultrasound

Prefrontal Cortex Activity Predicts Mental Fatigue in Young and Elderly Men During a 2 h “Go/NoGo” Task

Background: Although the effects of mental fatigue on cognitive–motor function and psychological state in young adults are well-documented, its effects in the elderly are not completely understood. The aim of this study was to estimate the effect of prolonged cognitive load on the indicators of psychological, cognitive, and motor functions.Methods: Fifteen young and 15 elderly men were asked to perform a 2 h “Go/NoGo” task. Psychological state (mood and motivation), cognitive (prefrontal cortex activity and cognitive performance), and motor (motor cortex excitability and grip strength) functions were measured before and after the task. During the 2 h task, both groups had a significantly similar increase in the number of “Incorrect NoGo” errors. Only in young men reaction time (RT) of “Incorrect NoGo” and intraindividual variability of RT of “Incorrect NoGo” significantly increased during task. After the task, handgrip strength decreased for the young men, whereas latency of motor evoked potentials prolonged both groups. Nevertheless, both groups indicated that they felt fatigue after the 2 h task; we observed that mental demand increased, whereas intrinsic motivation and mood decreased only in young men. Prolonged task decreased the switching/rest ratio of oxygenated hemoglobin for the young and the elderly men; however, greater for elderly than young men. Interestingly, the more the prefrontal cortex was activated before the 2 h task during the switching task, the fewer of “Incorrect NoGo” errors made by the young men and the greater the number of errors made by the elderly men.Conclusion: Because of the greater mental load and (possibly) greater activation of prefrontal cortex during the 2 h “Go/NoGo” task, there was greater mental and neuromuscular performance fatigue in young men than in elderly men

Comparison of DB, F1, F2, ir F2/Victor mongrel species castrated boars’ fattening and meat quality characteristics, when keeping them on concrete floor

From the written sources it is known that in Lithuania, during XVI – XIX centuries, mostly pigs were grown to satisfy meat usage demands. The number of bred pigs did not change since 1994, whereas the usage of pork has increased. In 2010 the number of pigs should reach 1,7 million, however in 2005 we had only 1 million of pigs. On purpose to raise healthy pigs that have good meat quality and taste characteristics, it is necessary to realize and understand pig breeding very well. Aim of the work: To assess fattening and meat quality characteristics of four species (DB, F1, F2 and F2/victor) castrated boars, when keeping them on concrete floor. Objectives of the work: To assess and determine the fattening characteristics of four species (DB, F1, F2 and F2/victor) castrated boars; To determine the meat quality parameters of four species (DB, F1, F2 and F2/victor) castrated boars. The tested animals – boars – castrates were divided into 4 groups: Big white pigs – 15 boars, F1 – 15 boars F2 – 12 boars, F2/Victor – 5 boars. The boars that have been weaned 4-6 weeks were selected for the tests. Tests were carried out untill boars reached realization mass: 95 – 105 kg. During the test the they were kept in one room, in different cots. All the animals – boars – castrates were marked by correspondent colour pins and numbered. Considering boars’ food nutrition needs, they have been fed with full-rate combinative fodders. Fattening and meat characteristics were determined for them, and the amount of muscles for lively boars was measured with device Piglog - 105. Conclusions: 1. Castrated boars‘ fattening characteristics were determined. 1.1. When analyzing castrated boars‘ average makeweight dynamics per 24 h, it was determined that during the whole test period the biggest average makeweight belonged to first generation mongrels (F1) – 0,896 kg, and the smallest belonged to Big white castrated boars (DB) – 0,851 kg. 1.2. The smallest average feed expenditure for obtaining 1 kg of makeweight was for F2/victor mongrels (2,77 kg), the biggest for Big white castrated boars (3,31 kg). 1.3. The biggest weight during all fattening months belonged to Big white castrated boars (DB): being 3 months old they weighted 40,15 kg; being 4 months old they weighted 60,0 kg; being 5 months old they weighted 88,8 kg. In the end of fattening period (6 months old) their weight was 114,64 kg. 1.4. During 3rd month of boars’ age the biggest makeweight per 24 h was obtained by F2/victor mongrels – 0,904 kg; during 4th month of boars‘ age the increase of makeweight was noticed, the biggest makeweight per 24 h belonged to F1 mongrels - 1,036 kg, it was on the average by 5,2 percent more than F2 mongrels‘ (p > 0,05), by 7,4 percent more than DB boars‘ (p 0,05); during 5th month the biggest makeweight per 24 h was obtained by F2 mongrels – 0,948 kg. During this month, the biggest makeweight downfall was recorded, it was for F1 mongrels, to 0,684 kg. 1.5. During 3rd month of boars‘ lifes, DB, F1 and F2 mongrels‘ castrated boars‘ feed expenditure for obtaining 1 kg of makeweight were equal – 2,4 kg; During 4th month of their lifes the feed expenditure of DB boars were 3,0 kg, it was on the average by 6,6 percent more than F1 and F2 mongrels‘ feed expenditure (p > 0,05), and by 16,6 percent less than F2/victor castrated boars‘ (p 0,05). In this age also a significant increase in expenditure was noticed for F1 mongrels, when comparing to 2nd and 3rd fattening months (from 2,8 to 4,7 kg). On the average during the whole fattening period the smallest feed expenditure remained for F2/victor mongrels – 2,77 kg. 2. The meat characteristics for castrated boars were determined: 2.1. The biggest castrated boars‘ weight before the killing was held by F2/victor mongrels – 114,6 kg. 2.2. The difference of carcass meat output percentage for all species of castrated boars was insignificant, however the biggest carcass meat output was gained from F2/victor mongrels – 71,1 %, the smaller output was gained from: DB mongrels – 0,2 %. 2.3. The biggest succulence percentage was in F2 mongrels’ carcass meat – 25,7 %, in DB it was by 1,0 percent smaller, in F2/victor mongrels‘ by 2,0 percent, and in F1 – by 2,3 percent smaller. The biggest bone percentage was found in F2/victor castrated mongrels, in carcass meat it was 14,9 %, by 1,6 percent less were found in F1 and F2 mongrels, and in DB – by 1,7 percent less. The smallest fat percentage in the carcass meat was observed in F2 mongrels – 6,6 percent, the bigger percentage of fat in carcass meat was found in F1 and F2/victor mongrels – by 2,7 percent more, and in DB boars – by 3,8 percent more than in F2 mongrels

Brent A Vadopalas' Quick Files

The Quick Files feature was discontinued and it’s files were migrated into this Project on March 11, 2022. The file URL’s will still resolve properly, and the Quick Files logs are available in the Project’s Recent Activity

Šildymo ir šaldymo poveikis raumenų valingosios ir elektrostimuliacijos sukeltos jėgos kaitai

The aim of this study was to investigate the effect of heating and cooling on time course of voluntary and electrically induced muscle force variation. Material and Methods. Ten volunteers performed 50 maximal voluntary and electrically induced contractions of the knee extensors at an angle of 120 degrees under the control conditions and after passive lower body heating and cooling in the control, heating, and cooling experiments. Peak torque, torque variation, and half-relaxation time were assessed during the exercise. Results. Passive lower body heating increased muscle and core temperatures, while cooling lowered muscle temperature, but did not affect core temperature. We observed significantly lower muscle fatigue during voluntary contraction compared with electrically induced contractions. Body heating (opposite to cooling) increased involuntarily induced muscle force, but caused greater electrically induced muscle fatigue. In the middle of the exercise, the coefficient of correlation for electrically induced muscle torque decreased significantly as compared with the beginning of the exercise, while during maximal voluntary contractions, this relation for torque remained significant until the end of the exercise. Conclusion. It was shown that time course of voluntary contraction was more stable than in electrically induced contractions

The effect of moderate-intensity aerobic physical load on the body temperature and running speed in athletes and physically inactive persons

Tiesioginis galūnių pašildymas gali smarkiai paveikti raumenų jėgą ir galingumą atliekant izokinetinius pratimus. Nustatyta, kad padidėjusi raumens temperatūra pagerina dinaminio krūvio kokybę. Mūsų tyrimo tikslas buvo nustatyti neintensyvaus aerobinio fizinio krūvio poveikį sportuojančių ir aktyviai nesportuojančių asmenų kūno temperatūrai ir bėgimo greičiui. Tyrime dalyvavo dvi grupės: sportuojantys ir aktyviai nesportuojantys asmenys. Sportuojančiųjų grupę sudarė 19–22 m. vyrai (n = 6; ūgis 182,7 ± 5,1 cm; kūno masė 72 ± 6,2 kg), aktyviai nesportuojančiųjų – sveiki 20–23 m. vyrai (n = 15; ūgis 181,7 ± 6,2 cm; kūno masė 71,7 ± 8,6 kg). Tiriama buvo du kartus skirtingomis dienomis, tarp tyrimų buvo savaitės pertrauka. Testai buvo atliekami 17–18°C temperatūroje. Prieš pradedant testavimą buvo matuojama kūno temperatūra – gyvsidabrinis termometras dedamas į pažastį 5 minutėms (Dollberg et al., 2003).Pirmasis tyrimas: tiriamieji bėgo 10 m iš vietos registruojant bėgimo greitį ir iš karto atliko neintensyvų aerobinį fizinį krūvį – bėgo 1 km, tada iš karto vėl bėgo 10 m iš vietos registruojant bėgimo greitį, vėl 1 km bėgimas ir trečiasis 10 m bėgimas iš vietos registruojant bėgimo greitį. Iš karto po paskutinio bėgimo buvo matuojama kūno temperatūra, 20 min pasyvus tiriamųjų poilsis ir vėl matuojama kūno temperatūra. Tada tiriamieji atliko paskutinį 10 m bėgimą iš vietos registruojant bėgimo greitį. Antrasis tyrimas: tiriamieji maksimaliomis pastangomis bėgo 10 m iš vietos atstumą 3 kartus iš eilės, tarp bėgimų pasyviai ilsėjosi 5 min. Iš karto po paskutinio bėgimo buvo matuojama kūno temperatūra. Pirmasis sportuojančių asmenų tyrimas parodė, kad taikant neintensyvų aerobinį fizinį krūvį kūno temperatūra padidėja 2,23 % (p < 0,05), taip pat 5,55 % (p < 0,05) padidėja ir 10 m bėgimų iš vietos greitis. Taikant 20 min pasyvų poilsį kūno temperatūra ir bėgimo greitis sumažėja iki pradinės reikšmės. Analogiški rezultatai gauti ir testuojant aktyviai nesportuojančius asmenis: pirmuoju atveju jų kūno temperatūra pakito 1,37 % (p < 0,05), bėgimo greitis padidėjo 4,99 % (p < 0,05), o taikant pasyvų poilsį rezultatai sumažėjo. Antrojo tyrimo metu, kai buvo netaikomas neintensyvus aerobinis fizinis krūvis, abiejų grupių tiriamųjų tiek kūno temperatūra, tiek ir bėgimo greičiai statistiškai patikimai nepakito. Vadinasi: 1) aerobinis fizinis krūvis padidino sportuojančių ir aktyviai nesportuojančių asmenų kūno temperatūrą ir bėgimo greitį; 2) taikant 20 min pasyvų poilsį po fizinio krūvio kūno temperatūra ir bėgimo greitis sumažėjo iki pradinės reikšmės; 3) netaikant aerobinio fizinio krūvio abiejų grupių tiriamųjų bėgimo greitis nedidėjo ir kūno temperatūra išliko nepakitusi.Direct heating of body limbs can have a strong effect on muscle force and strength during isokinetic exercises (Ball et. al., 1999). B. Drust et al. (2005)substantiate, that increased muscle temperature improve dynamic load quality. The aim of the study is to determine the effect of moderate-intensity aerobic physical load on the body temperature and running results in athletes and physically inactive persons. Research organisation. There were two groups in this research: athletes and physically inactive. Athletes group included 19-22 years old males (height 182,7 ± 5,1 cm; weight 72 ± 6,2 kg; n = 6). Physically inactive persons group included healthy males aged 20-23 (height 181,7 ± 6,2 cm; weight 71,7 ± 8,6 kg, n = 15). The test lasted for two days in a 17–18°C temperature environment. On the first research day, before testing, the body temperature was measured placing a mercury thermometer in the armpit for 5 minutes (Dollberg et. al., 2003). Before performing the test, the subjects did stretching exercises without warm up. The start line was curved 70 cm before the line, indicating the beginning of 10 m distance. The take-off foot was placed before the start line, while the trail leg was behind it (1-2 feet). The subjects started to run independently, i.e. without the starter’s command. The subjects ran the distance at maximum efforts as fast as possible with run time recorded (Mamkus et. al., 2004). After one such run race immediately 1 km run followed (the distance had to be covered in 5 min.), and again 10 m run from a standing static position. The described activities were repeated 3 times. The body temperature was measured and one additional 10 m run from a standing static position was performed immediately after the last run and then after 20 min. On the second research day, the beginning phase of the test was the same as on the first day, however, this time the subjects ran 10 m from a standing static position 3 times in a sequence with 5 min rest between the trials. The body temperature was measured immediately after the last run. Both groups performed the same research protocol. [...