Although birds have genetically determined sex, the sex ratio has been reported to deviate from parity in several studies. Temperature-dependent sex determination, which is common in reptiles, is absent in birds. However, females are able to adjust their investment into eggs according to the sex of the embryo, which may cause sex-specific embryonic mortality. Incubation temperature may also cause sex-biased embryonic mortality, and it may differentially affect the phenotype of male and female hatchlings. We aimed to investigate differences between male and female Mallard embryos regarding their egg size, mortality during incubation and hatchling phenotype in relation to incubation temperature. Mallard eggs were incubated under six constant incubation temperatures (ranging from 35.0 to 38.0 °C). Hatchlings were weighed, and their morphological traits were measured. We determined the sex of hatchlings and unhatched embryos by genetic analysis and found higher male embryonic mortality at 35.5 °C (44 males vs. 28 females) and a higher proportion of female hatchlings at 38 °C (24 males vs. 38 females); however, these results were not statistically significant. Our results suggest that Mallard females do not differentiate quantitatively between sexes during egg production. Male hatchlings were significantly larger but not heavier than females. The size difference between sexes was most pronounced at temperatures around 36 °C, which is the mean temperature of naturally incubated Mallard eggs.
- MeSH
- Anseriformes embryology physiology MeSH
- Poultry embryology physiology MeSH
- Embryonic Development * MeSH
- Incubators MeSH
- Sex Ratio * MeSH
- Temperature * MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
The reproductive success of precocial birds depends on investments in clutch formation and incubation. Egg quality strongly affects the phenotypic traits correlated with survival of the hatchling, but parental ability to maintain incubation temperature can also influence hatchling outcomes. The effect of incubation temperature on hatchling phenotype has been widely studied in reptiles but not in birds. The aim of this study was to explore the effects of egg mass and incubation temperature on the incubation period, hatchability, and hatchling phenotype of the mallard (Anas platyrhynchos). Mallard eggs were incubated under six constant incubation temperatures (ranging from 35.0° to 39.0°C). Hatchlings were weighed, and their structural size was measured. Some hatchlings were used for an examination of residual yolk sac mass and basic chemical composition of the yolk-free body. All investigated phenotypic traits except for chemical composition were positively correlated with egg mass. Incubation temperature did not affect hatchling body mass, but increased temperatures led to a decreased yolk-free body mass and structural size of hatchlings and to increased yolk sac mass. Our results suggest that there is a trade-off between the yolk-free body size and energetic reserves in the form of the yolk sac and that this trade-off is modulated by incubation temperature.
- MeSH
- Embryo, Nonmammalian embryology MeSH
- Embryonic Development physiology MeSH
- Phenotype MeSH
- Ducks embryology MeSH
- Animals, Newborn MeSH
- Ovum chemistry MeSH
- Temperature * MeSH
- Body Size MeSH
- Yolk Sac chemistry MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Knowledge of embryo development is essential to the application of reproductive biotechnology in aquaculture, including for pikeperch Sander lucioperca. We describe pikeperch embryo development and demonstrated effects of temperature on the duration of embryogenesis. Developmental stages in embryos incubated at 15 °C were identified as zygote, 0-1.5 h post-fertilization (hpf); cleavage, 2.5-7.5 hpf; blastula, 9-18.75 hpf; gastrula, 21-39, hpf; segmentation, 45-105 hpf; and hatching, 125-197 hpf. Additional groups of eggs were fertilized and incubated at 10, 15, 20, and 25 °C to document stages of development, development rate, and survival. The optimal fertilization and incubation temperature was shown to be 15 °C, with the highest fertilization, survival, and hatching rates. Embryo development was slower at 10 °C, with 45% of fertilized embryos surviving to hatching. Development was accelerated at 20 °C, and resulted in a 56% survival rate of fertilized embryos. At 25 °C, embryos did not develop to the blastula stage. Pikeperch could be a valuable percid model for research in which flexible incubation temperatures is required.
- MeSH
- Embryo, Nonmammalian physiology MeSH
- Embryonic Development MeSH
- Perciformes embryology MeSH
- Temperature * MeSH
- Water * MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Výsledek elektromyografického (EMG) vyšetření může být ovlivněn mnoha faktory. Zcela zásadní vliv na vedení impulzu nervem má kožní teplota, kdy snížení teploty vede ke snížení rychlosti vedení a prodloužení distálních latencí. Metodika proto doporučuje teplotu kůže 32–36 °C a pod tuto hodnotu není možno považovat vyšetření za validní. Při nedostatečné kožní teplotě je třeba končetiny pacienta nejdříve nahřát. Jako nouzové řešení při nemožnosti nahřátí, lze použít korekci zjištěné hodnoty distální latence o 0,3 ms nebo o 0,1 ms za každý stupeň pod standardní teplotu. Cílem této práce bylo srovnání výsledků měření distální motorické latence (DML) středových nervů při nedostatečné kožní teplotě a po zahřátí rukou na standardní teplotu, a dále ověření spolehlivosti výsledku měření DML po použití uvedených korekcí při screeningovém EMG v rámci pracovnělékařských prohlídek. Měření DML středových nervů v oblasti zápěstí bylo realizováno přístrojem EMG TruTrace 2, jehož součástí je i zařízení pro kontinuální měření kožní teploty. Celkem bylo vyšetřeno 40 osob – nejdříve při pokojové teplotě, kdy kožní teplota rukou nedosahovala 32 °C, poté po zahřátí rukou na standardní teplotu 33–36 °C. Hodnoty DML byly srovnávány párovým t-testem a hodnoceny na hladině statistické významnosti 5 %. Pro zpracování dat byl použit program Stata v. 13. Ve srovnání s výsledky DML po zahřátí na standardní teplotu byly hodnoty DML při pokojové teplotě statisticky signifikantně prodlouženy (p < 0,001), což vedlo k falešně pozitivnímu výsledku u 55 % nálezů. Naopak, použití korekce 0,3 ms/1 °C výsledné hodnoty DML významně snížilo (p < 0,001), a tím vedlo k falešně negativním výsledkům. Jako spolehlivá nebyla potvrzena ani korekce 0,1 ms/1 °C, zejména u osob s hraničním a abnormálním nálezem, u kterých byly statisticky významné rozdíly (p < 0,05). Závěrem lze shrnout, že nedodržení podmínek standardní teploty kůže při vyšetření DML představuje významné riziko falešně pozitivních nálezů. Výstupy studie neprokázaly spolehlivost uvedených korekcí a jejich použití v praxi může být významným zdrojem chyb, zejména jedná-li se o abnormální nebo hraniční nálezy. Abnormální nálezy z EMG screeningu jsou sice verifikovány vyšetřením u neurologa, přesto i při realizaci screeningového testu je nezbytné respektovat standardní metodiku včetně doporučené kožní teploty. Dodržování uvedených podmínek tak vede k minimalizaci chyb při vyšetření i interpretaci výsledku.
The result of an electromyography (EMG) test may be influenced by many factors. A fundamental effect on nerve impulse conduction has a skin temperature. Its reduction leads to a reduced conduction velocity and distal latency prolongation. Therefore the methodology recommends the skin temperature between 32–36 °C and below this value the examination cannot be considered valid. In case of insufficient skin temperature, the patients’ limbs are necessary to be heat up first. If heat up is not possible an emergency solution is applied by the correction of observed distal latency values of 0.3 ms or of 0.1 ms for every degree under the standard temperature. The aim of this study was to compare the measurement results of the distal motor latency (DML) of median nerves at the lack of skin temperature and after heating hands at standard temperature. The further goal was to verify the reliability of the DML measurement results after applying the above corrections during the screening EMG within occupational medicine examinations. DML measurement of median nerves in wrist area was realized by the EMG TruTrace 2 device, which also includes a device for continuous measurement of skin temperature. In total 40 persons were examined – first at room temperature, when the skin temperature of hands did not reached 32 °C, and retested after heating hands up to the standard temperature 33–36 °C. DML values were compared by a paired t-test and evaluated on the 5% level of significance. The data analysis was conducted using the software STATA v.13. In comparison with the DML results after heating up to the standard temperature the DML values at room temperature were significantly prolonged (p < 0.001) that led to false positive results in 55 % of the findings. Conversely, if correction 0.3 ms/1 °C was applied the resulting DML values significantly decreased (p < 0.001) and thus led to false negative results. Neither the correction 0.1 ms/1 °C has not been confirmed, as reliable especially in persons with borderline, and abnormal findings, whose results showed statistically significant differences (p < 0.05). In conclusion, it can be summarized that a lack of compliance with the standard skin temperature during the DML testing poses a significant risk of false positive findings. The study results did not confirm the reliability of the corrections which use in practice may be a significant source of errors, especially in the case of abnormal or borderline findings. Although the abnormal findings of the EMG screening are verified by a neurologist examination, the standard methodology including recommended skin temperature is necessary to be respected during the screening test. Compliance with those conditions lead to a minimization of errors in tests and interpreting the results.
- Keywords
- kožní teplota, pracovnělékařské prohlídky, distální motorická latence,
- MeSH
- Adult MeSH
- Electromyography methods standards statistics & numerical data MeSH
- False Negative Reactions MeSH
- False Positive Reactions MeSH
- Middle Aged MeSH
- Humans MeSH
- Neural Conduction MeSH
- Median Nerve MeSH
- Reaction Time MeSH
- Occupational Health Services MeSH
- Carpal Tunnel Syndrome * diagnosis prevention & control MeSH
- Skin Temperature * MeSH
- Wrist innervation MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
The method of pyridine temperature-programmed desorption (TPD) was applied for the measurement of acid properties of in situ reduced copper catalysts on silicate support. A thermal-conductivity detector (TCD) was used for the detection of TPD spectra of pyridine. The combination of flame-ionization detector and thermal conductivity detector shows that the region of TPD spectrum with the peak maxima T(MAX1)=350 degrees C is a superposition of the TCD response on spectra of desorbed pyridine, water and carbon dioxide, desorbing simultaneously from the catalyst surface. The method for the elimination of H(2)O and CO(2) on the layer of NaOH was tested and the pure TPD spectrum of pyridine was obtained. The exact determination of pyridine concentration allows to estimate the amount of weak and medium acid centers of the catalyst. The gas chromatography with the mass spectroscopy (GC-MS) analyses was used for the interpretation of high temperature region of the pyridine TPD spectra (T(MAX2)=620 degrees C). It was found that pyridine bonded on the strong acid centers is decomposed to N(2) and CO under very high temperature. The available chromatographic method for the separation of components present in pyridine TPD spectrum in the high-temperature region was suggested. The method for the quantification of strong acidity of copper-supported catalyst was found.
- MeSH
- Humans MeSH
- Software Design MeSH
- Body Burden MeSH
- Computers MeSH
- Body Temperature MeSH
- Check Tag
- Humans MeSH
This study aimed to investigate the effects of performing either eccentric-only (ECC) or eccentric-concentric (ECC-CON) back squats (BS) with a supramaximal load on countermovement jump (CMJ) performance. Changes in front thigh skin surface temperature and mechanical properties (oscillation frequency and stiffness) of the vastus lateralis were also examined. Fourteen male powerlifters participated in this study (age: 22.5 ± 2.3 years, body weight: 84.2 ± 11.1 kg, height: 178 ± 7 cm, training experience: 5.4 ± 1.6 years, BS one-repetition maximum [1RM]: 177 ± 22.8 kg). The experimental sessions included 2 sets of 2 BS at 110% 1RM of either ECC-CON (load distributed by half on the barbell [55%] and on weight releasers [55%]) or ECC (only eccentric phase of BS) and CTRL with no CA applied. CMJ performance, mechanical properties, and skin surface temperature were measured before and at the third, sixth, ninth, and 12th min. After each protocol, only the ECC-CON condition led to a significant increase in CMJ height after individual optimal rest time compared to pre-CA (38.1 ± 5.2 vs. 39.8 ± 5.0 cm; p = 0.003; effect size [ES] = 0.32; Δ = 4.9 ± 5.0%) with a significant rise in skin surface temperature (32.98 ± 1.24 vs. 33.69 ± 0.96°C; p = 0.006; ES = 0.62; Δ = 2.2 ± 2.6%) and no significant changes in mechanical properties of the vastus lateralis. The ECC-CON condition led to a significant acute improvement in CMJ height and an increase in front thigh skin surface temperature among powerlifters. The ECC-CON supramaximal lower limb PAPE protocol should be effectively used among males representing high levels of lower limb muscle strength (>2 × body mass).
- MeSH
- Biomechanical Phenomena MeSH
- Quadriceps Muscle physiology MeSH
- Adult MeSH
- Muscle, Skeletal physiology MeSH
- Humans MeSH
- Young Adult MeSH
- Resistance Training MeSH
- Athletic Performance * physiology MeSH
- Thigh physiology MeSH
- Muscle Strength physiology MeSH
- Skin Temperature * physiology MeSH
- Weight Lifting * physiology MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
Subseafloor sediments present an untapped source of novel bacterial species with industrially important bioactivities. Subseafloor core samples collected during the Integrated Ocean Drilling Program Expeditions 315, 316, and 331 and stored in Kochi Core Center at -80 °C for 1 to 4 years were used for cultivation-based study of viable actinomycetes. In total, more than 100 actinomycete-like colonies were isolated from two deep-frozen subseafloor sediment samples. Isolated actinomycetes showed close similarity to known Actinotalea, Dietzia, Gordonia, Isoptericola, Microbacterium, Nocardia, Rhodococcus, Pseudonocardia, Streptomyces, and Tsukamurella species and were halotolerant. Bioactivity assays revealed that two of the isolates were producing potent antibacterial compound(s) and one isolate was having antifungal activity. Our study demonstrated that deep-frozen subseafloor core samples could be a potential source of viable actinomycetes, which may be used in drug discovery.
A rapid method using programmed temperature vaporiser injection-low-pressure gas chromatography-high-resolution time-of-flight mass spectrometry (PTV-LP-GC-HR-TOF-MS) for the analysis of multiple pesticide residues in fruit-based baby food was developed. The fast and inexpensive buffered QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction method and "conventional" approach that employs ethyl acetate extraction followed by gel permeation chromatography (GPC) cleanup were employed for sample preparation. A PTV injector in solvent venting mode was used to reduce volume of acetonitrile and acetic acid (from the buffered QuEChERS extracts) that caused higher column bleed without their elimination. Otherwise, the time-to-digital converter would become saturated in HR-TOF-MS. For fast GC separation allowing analysis of 100 analytes within a 7 min runtime, both a high temperature programming rate and vacuum conditions in a megabore GC column were employed. The use of HR-TOF-MS allowed the unbiased identification and reliable quantification of target analytes through the application of a narrow mass window (0.02 Da) for extracting analyte ions and the availability of full spectral information even at very low levels. With only a few exceptions, the lowest calibration levels for the pesticides tested were
- MeSH
- Aminoimidazole Carboxamide analogs & derivatives analysis MeSH
- Food Analysis methods MeSH
- Time Factors MeSH
- Endosulfan analysis MeSH
- Financing, Organized MeSH
- Hydantoins analysis MeSH
- Isomerism MeSH
- Acetic Acid chemistry MeSH
- Fruit chemistry MeSH
- Gas Chromatography-Mass Spectrometry methods MeSH
- Buffers MeSH
- Reproducibility of Results MeSH
- Pesticide Residues analysis isolation & purification MeSH
- Temperature MeSH
- Pressure MeSH
- Volatilization MeSH
