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1.
J Dairy Sci ; 106(12): 8847-8860, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37641313

RESUMO

Indian dairy enterprise is dominated by smallholder dairy farms that contribute 72% of the country's total milk production. These smallholder dairy farms are often considered to emit substantial greenhouse gases (GHG) but are poor in productive performances. Therefore, it is crucial to estimate the carbon footprint (CF) of milk production of the smallholder Indian dairy farms. The primary objectives of the study were (1) Assessing the CF of milk production of smallholder dairy farms through life cycle analysis in south-interior Karnataka, India; (2) Identifying the hotspots of GHG emissions and significant factors influencing the CF of milk production in smallholder dairy production system. The study accounted GHG emissions from different sources and considered multiple functions of the smallholder production system. Estimations were made based on primary data collected from 47 farms and associated secondary data. For estimating the CF of milk production, the emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) on a CO2-equivalent (CO2-eq) basis from feed production, enteric fermentation, manure management, transport and energy usage were allocated to fat- and protein-corrected milk (FPCM) based on mass balance, price (crop byproducts and residues) and feed digestibility. Principal component analysis and stepwise linear regression analysis were performed to identify the major factors influencing the CF. The average total GHG emissions (kg CO2-eq yr-1 farm-1) attributable to milk production based on mass, economic, and digestibility allocations were 8,936, 8,641, and 8,759, respectively. The contributions of CH4, N2O, and CO2 to the total farm GHG emission were 70.6%, 20.5%, and 7.69%, respectively. The major emission hotspots were CH4 emission from enteric fermentation (66.8%) and GHG emission from feed production (23.0%). The average CF of cradle-to-dairy cooperative milk production varied from 1.45 to 1.81 kg CO2-eq kg FPCM-1. The CF of milk production was more than 2-fold greater, when milk yield was below 3,500 kg lactating cow-1 yr-1. The FPCM yield 100 kg body weight-1, dry matter intake, and CH4 emission from manure management were the strongest determinants of the CF and explained 83.4% of the observed variation. The study emphasized the importance of considering multiple functions of a mixed crop-livestock-based dairy production system for estimating CF per unit of product. The results suggest that maintaining high-yielding dairy animals and adopting appropriate feeding strategies for better feed utilization are the possible effective interventions for reducing the CF of milk production.


Assuntos
Pegada de Carbono , Gases de Efeito Estufa , Bovinos , Feminino , Animais , Leite/química , Fazendas , Lactação , Dióxido de Carbono/análise , Esterco , Indústria de Laticínios/métodos , Índia , Gases de Efeito Estufa/análise , Metano/análise , Efeito Estufa
2.
Nanotoxicology ; 13(1): 119-141, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30182766

RESUMO

This paper presents a comprehensive review of European Union (EU) legislation addressing the safety of chemical substances, and possibilities within each piece of legislation for applying grouping and read-across approaches for the assessment of nanomaterials (NMs). Hence, this review considers both the overarching regulation of chemical substances under REACH (Regulation (EC) No 1907/2006 on registration, evaluation, authorization, and restriction of chemicals) and CLP (Regulation (EC) No 1272/2008 on classification, labeling and packaging of substances and mixtures) and the sector-specific pieces of legislation for cosmetic, plant protection and biocidal products, and legislation addressing food, novel food, and food contact materials. The relevant supporting documents (e.g. guidance documents) regarding each piece of legislation were identified and reviewed, considering the relevant technical and scientific literature. Prospective regulatory needs for implementing grouping in the assessment of NMs were identified, and the question whether each particular piece of legislation permits the use of grouping and read-across to address information gaps was answered.


Assuntos
Nanoestruturas/classificação , Nanoestruturas/toxicidade , Nanotecnologia/legislação & jurisprudência , Nanotecnologia/métodos , Determinação de Ponto Final , União Europeia , Regulamentação Governamental , Humanos , Estudos Prospectivos , Medição de Risco
3.
Int J Biometeorol ; 60(9): 1311-23, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26698161

RESUMO

A study was conducted to assess the impact of heat and nutritional stress simultaneously on the adaptive capability as indicated by behavioral and physiological responses, plasma heat shock protein 70 (HSP70) level, and peripheral blood mononuclear cells (PBMC) HSP70 gene expression in goats. Twenty-four adult Osmanabadi bucks (average body weight (BW) 16.0 kg) were used in the present study. The bucks were divided into four groups viz., C (n = 6; control), HS (n = 6; heat stress), NS (n = 6; nutritional stress), and CS (n = 6; combined stress). The study was conducted for a period of 45 days. C and HS bucks had ad libitum access to their feed while NS and CS bucks were under restricted feed (30 % intake of C bucks) to induce nutritional stress. The HS and CS bucks were exposed to solar radiation for 6 h a day between 10:00 a.m. and 4:00 p.m. to induce heat stress. The data was analyzed using repeated measures analysis of variance. The standing time differed significantly (P < 0.01) between ad libitum fed groups (C and HS) and restricted feeding groups (NS and CS). The highest (P < 0.01) lying time was recorded in the CS group while the lowest in the C and HS groups. The highest (P < 0.01) drinking frequency was also recorded in the CS group. Water intake recorded was significantly (P < 0.01) higher in both the HS and CS groups. The highest respiration rate (RR), pulse rate (PR), and rectal temperature (RT) during the afternoon were also recorded in the CS group. Further, skin temperature of the head, flank, and scrotum during the afternoon was also higher (P < 0.01) in the CS group. In addition, both plasma HSP70 concentration and PBMC HSP70 messenger RNA (mRNA) transcript expression were also significantly (P < 0.01) higher in the CS group. It can be concluded from this study that when two stressors occur simultaneously, they may have severe impact on adaptive capabilities of Osmanabadi bucks as compared to that would occur individually. Further, the study indicated that lying time, drinking frequency, RR, RT, plasma HSP70, and PBMC HSP70 gene expression may act as ideal biological markers for assessing the impact of CS on adaptive capabilities in bucks.


Assuntos
Privação de Alimentos/fisiologia , Cabras/fisiologia , Proteínas de Choque Térmico HSP70 , Transtornos de Estresse por Calor/veterinária , Temperatura Alta/efeitos adversos , Estresse Fisiológico/fisiologia , Animais , Comportamento Animal , Temperatura Corporal , Ingestão de Líquidos , Expressão Gênica , Cabras/sangue , Proteínas de Choque Térmico HSP70/sangue , Proteínas de Choque Térmico HSP70/genética , Transtornos de Estresse por Calor/sangue , Transtornos de Estresse por Calor/genética , Transtornos de Estresse por Calor/fisiopatologia , Leucócitos Mononucleares/metabolismo , Masculino , Pulso Arterial , RNA Mensageiro/metabolismo , Taxa Respiratória , Estresse Fisiológico/genética
4.
J Anim Physiol Anim Nutr (Berl) ; 97(6): 1051-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23062231

RESUMO

The effect of concentration and addition method of glycerol on the quality of cryopreserved mithun (Bos frontalis) spermatozoa was investigated. Semen samples were collected from five healthy mithun bulls through rectal massage method and cryopreserved in liquid nitrogen. The samples were diluted in Tris-egg yolk-glycerol extender, equilibrated for 4 h at 4 °C and loaded into 0.50-ml straws. The straws were then frozen in liquid nitrogen vapour for 10 min and finally plunged into liquid nitrogen for storage. The required amount of glycerol was added into the diluted samples either in a single dose (3%, 4%, 5%, 6% or 7%; added at 37 °C immediately before equilibration) or in split doses (5%, 6% or 7%; the total amount was divided into four equal parts, and a part was added at 37 °C immediately before equilibration, and the remaining parts were added subsequently at 1, 2 and 3 h of equilibration at 4 °C). In the single-dose addition method, following freeze-thawing, greater (p < 0.05) motility (%) and proportion of live spermatozoa with intact acrosome (LSIA, %) in 5% glycerol (40.6 ± 1.7 and 43.4 ± 1.8 respectively) and lesser (p < 0.05) total morphological abnormalities (%) in 5% (14.1 ± 0.8) and 6% (13.7 ± 1.0) glycerol were observed compared to the other glycerol concentrations. In the split-dose addition method, following freeze-thawing, greater (p < 0.05) motility (%) and LSIA proportion (%) were found in 5% (50.2 ± 1.9 and 53.3 ± 1.8 respectively) compared to 6% or 7% glycerol, but the total morphological abnormalities were not different among the glycerol concentrations. In addition, in all the glycerol concentrations, better (p < 0.05) post-freeze-thaw motility and LSIA proportions were observed when glycerol was added in split doses compared to a single dose. In conclusion, Tris-egg yolk extender with 5% glycerol added in split doses was found most suitable for cryopreserving mithun sperm.


Assuntos
Bovinos/fisiologia , Criopreservação/veterinária , Crioprotetores/farmacologia , Glicerol/farmacologia , Análise do Sêmen/veterinária , Espermatozoides/efeitos dos fármacos , Animais , Masculino , Sêmen/efeitos dos fármacos , Sêmen/fisiologia , Espermatozoides/fisiologia
5.
J Anim Physiol Anim Nutr (Berl) ; 95(6): 756-61, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21198956

RESUMO

The effect of method and time of first colostrum feeding on the concentration of serum immunoglobulin (Ig) was evaluated in mithun (Bos frontalis) calves. The hypotheses were that the variable method and time of first colostrum feeding might affect the level of serum Ig and in turn the growth performance and health status of the claves during the early age. The newborn calves were randomly allotted to one of the four experimental groups - G-1: allowed to suckle the dam at own choice, G-2: separated immediately after birth and allowed to suckle the dam first at 6 h and then at own choice, G-3: bottle fed ad libitum colostrum of its own dam first at 6 h and then at 6-h intervals until 24 h, G-4: bottle fed ad libitum colostrum of its own dam within 1 h, at 6 h and then at 6-h intervals until 24 h. The concentrations of IgG, IgM, and IgA were lowest (p < 0.01) at birth and increased following colostrum feeding irrespective of the experimental group. Highest concentrations of all the Ig classes were observed at 12-24 h after birth. The concentrations then transiently decreased from day 7 to 14, and then steadily increased after day 28. The concentrations of IgG (p < 0.01) and IgA (p < 0.05) were higher in G-1 in relation to the other groups during the first week after birth. Similarly, higher concentration of IgA (p < 0.05) was found in G-1 in relation to the other groups during the rest of the experimental period. The apparent absorption efficiency of colostral IgG was higher (p < 0.05) in G-4 in relation to G-3. Growth rate and health status were not influenced by the method and time of first colostrum feeding. In conclusion, a 6-h delay in the first colostrum feeding reduced the level of serum Ig noticeably.


Assuntos
Colostro/metabolismo , Imunoglobulinas/sangue , Ruminantes/sangue , Ruminantes/fisiologia , Aumento de Peso/fisiologia , Animais , Animais Recém-Nascidos/sangue , Animais Recém-Nascidos/fisiologia , Fatores de Tempo
6.
Plant Dis ; 95(5): 612, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-30731965

RESUMO

Eastern hemlock (Tsuga canadensis) is an ecologically and economically important conifer from the north-central United States to the east coast of North America to the southern Appalachian Mountains. In early spring 2010, blighted shoot tips of eastern hemlock were observed at widely separated locations in the Chattahoochee National Forest in north Georgia. Damage did not appear to be directly related to hemlock woolly adelgid (Adelges tsugae) activity, which was sporadic or absent in some areas where symptoms were observed. A preliminary survey in March 2010 revealed that incidence of blighted shoots on individual trees varied, but was as high as 70%. Stems of shoots produced the previous year were frequently necrotic, had lost needles, and bore pycnidia with hyaline, two-celled conidia consistent with those of Sirococcus tsugae (2,3). Later in the spring and summer, shoots of the current year's growth became blighted, with sporulation of S. tsugae also on dead and dying needles. While S. tsugae previously has been reported on T. heterophylla, T. mertensiana, Cedrus atlantica, and C. deodara in western North America, it has only recently been reported on eastern hemlock (1), and its ability to induce shoot blight has not been proven. Pure cultures (2,3) were obtained on streptomycin-amended potato dextrose agar (PDA) and their identity was confirmed by species-specific PCR primers (4). Nuclear rDNA internal transcribed spacer sequence (554 nucleotides) also was obtained for isolate 10-05 and deposited in GenBank (Accession No. HQ256769). This sequence was found to be identical to sequences previously deposited for S. tsugae isolates. Isolate 10-05 and a second isolate (10-06) were used to inoculate potted 2-year-old eastern hemlock seedlings in a growth chamber at 20°C with a 16-h photoperiod. Conidia were collected by flooding 1-month-old colonies on PDA with sterile water. Expanding shoots on one branch of each seedling were wounded using scissors to cut the tips off needles and stems, while another branch remained nonwounded. Ten seedlings per isolate were inoculated by spraying to runoff with a suspension of 5 × 106 conidia ml-1 in sterile water, and five similarly treated control seedlings were sprayed with sterile water. Seedlings were covered with plastic bags to maintain high humidity for 4 days. Germination of conidia of each isolate incubated on water agar in this growth chamber was >80% after 24 h. Symptoms were evaluated and reisolation was attempted on streptomycin-amended PDA 2 months after inoculation. Symptoms of seedlings inoculated with either isolate included chlorotic and necrotic needle spots, browning of cut edges of needles, browning and death of needle tips and entire needles, death of stem tips with retention of dead needles, and needle loss. Symptoms of control seedlings were limited to slight browning of cut edges of needles. The fungus was reisolated from wounded shoots of 17 of 20 inoculated seedlings and nonwounded shoots of 5 of 20 inoculated seedlings and was not cultured from control seedlings. To our knowledge, this is the first report of S. tsugae in Georgia and also the first demonstration of its ability to produce symptoms that have been attributed to it on any tree species. References: (1) M. Miller-Weeks and W. Ostrofsky. USDA. Forest Service. Online publication. NA-PR-01-10, 2010. (2) A. Y. Rossman et al. For. Pathol. 38:47. (3) D. R. Smith et al. For. Pathol. 33:141, 2003. (4) D. R. Smith and G. R. Stanosz. For. Pathol. 38:156, 2008.

7.
J Chem Phys ; 132(2): 024504, 2010 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-20095684

RESUMO

We have investigated the mechanism of exciton-exciton annihilation in organic lanthanide complexes by measuring the excitation density dependence of photoluminescence yield in neat films of a model europium chelate. The observed luminescence efficiency reduction at high excitation intensities has been attributed to the operation of the mutual annihilation of the ligand singlet excitons. The second order interaction rate constant, the exciton diffusivity, and the singlet exciton diffusion length in this material have been determined. These results were used to evaluate the role of exciton annihilation in organic light emitting diodes, lanthanide-based organic lasers, and light up-converters. Indications concerning the optimization of the performances of such devices have also been given.

8.
Phys Chem Chem Phys ; 11(43): 10152-6, 2009 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-19865771

RESUMO

We present a single layer, polymer white light emitting diode (WOLED) based on novel organic lanthanide complexes. The device is solution processed and possesses CIE coordinates of (0.33, 0.38), corresponding to a high color purity white light emission. The electroluminescence in this diode is found to originate from both the direct charge trapping on the lanthanide complexes and from the efficient diffusion-assisted long-range energy transfer between the conductive matrix and these emissive dopants. An expression for the steady-state transfer efficiency is given, the role of excitation diffusion in the system under study is quantitatively evaluated, and the values for the singlet exciton diffusion coefficients and diffusion lengths in the host are determined.

9.
Phys Rev Lett ; 102(8): 087404, 2009 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-19257785

RESUMO

We have investigated the influence of the magnetic field on the triplet-triplet annihilation process in organic films using a model multicomponent system for blue delayed up-conversion photoluminescence. In such a way, we have derived simple analytical expressions to estimate the overall annihilation probability, outlining the peculiar role played by the disorder and demonstrating that the triplet-triplet fusion in solid films is a diffusion limited process.

10.
Animal ; 2(6): 879-82, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22443667

RESUMO

The study describes the standardization of a suitable semen cryopreservation protocol for the first time in mithun (Bos frontalis) and birth of the first mithun calf through artificial insemination. The semen samples were collected from adult bulls through the rectal massage method and cryopreserved in liquid nitrogen using tris-egg yolk-glycerol diluent. The diluted semen samples were packaged in 0.50 ml straws and kept at 5°C for 4 h for equilibration. Following the equilibration, the straws were frozen into liquid nitrogen vapour for 10 min and then plunged into liquid nitrogen for storage. It was observed that the progressive motility (%) decreased significantly (P < 0.01) in cryopreserved semen (43.3 ± 4.1) compared with fresh samples (76.6 ± 3.3). The percentages of live spermatozoa (P < 0.01) and spermatozoa with intact acrosome (P < 0.05) also decreased significantly in cryopreserved semen (54.0 ± 3.3 and 64.6 ± 5.3) compared with fresh samples (79.3 ± 2.6 and 85.3 ± 1.8). Simultaneously, the total morphological abnormality (%) was found to be significantly (P < 0.01) higher in cryopreserved samples (15.46 ± 2.68) than in fresh semen (3.85 ± 0.63). A total of three mithun cows were inseminated using the cryopreserved semen. All the cows conceived following insemination and gave birth to healthy calves. The study revealed that mithun semen can be cryopreserved efficiently using tris-egg yolk-glycerol diluent, which can be further used for artificial insemination.

11.
J Immunoassay Immunochem ; 28(2): 107-17, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17424829

RESUMO

The present study was designed to develop and validate a simple and sensitive radioimmunoassay (RIA) procedure to estimate FSH in mithun (Bosfrontalis) plasma. The assay was carried out in 100 [L of mithun plasma. The bovine FSH standards (10 to 5000 pg/100 microL/tube) in hormone-free plasma were used in the assay. The sensitivity of the assay was 20 pg/100 microL/tube, which corresponded to 0.20 ng/mL plasma. The 50% relative binding sensitivity of the assay was 80 pg/100 microL/tube, which corresponded to 0.80 ng/mL plasma. The intra- and inter-assay coefficients of variation were 4.6% and 12.4%, respectively. The biological validation of the assay was carried out in plasma samples that were collected during different stages of the estrous cycle. In the entire estrous cycle, plasma FSH concentration (p < 0.01) attained two peaks (on day 3 to 4 before estrus 5.1 +/- 0.3 ng/mL and on the day of estrus 6.9 +/- 0.2 ng/mL). FSH concentration remained at basal level (1.3 +/- 0.1 to 1.6 +/- 0.2 ng/mL) during day 4 to 16 of the estrous cycle. The concentration of plasma FSH was found to be significantly (p < 0.05) higher (4.9 +/- 0.3 to 6.8 +/- 0.5 ng/mL) until 48 h following the estrus onset. In conclusion, the RIA procedure that was developed in the current study is sufficiently reliable and sensitive to estimate different physiological levels of FSH in mithun plasma.


Assuntos
Bovinos/fisiologia , Ciclo Estral/sangue , Hormônio Foliculoestimulante/sangue , Radioimunoensaio/métodos , Animais , Feminino , Sensibilidade e Especificidade
12.
Anim Reprod Sci ; 101(3-4): 257-64, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17095169

RESUMO

The objective of the present study was to investigate the possibility of preserving mithun (Bos frontalis) spermatozoa at refrigeration temperature using tris-egg yolk diluent. Semen samples were collected from four adult mithun bulls through rectal massage method. Good quality semen samples (n=30) were preserved at 4 degrees C using tris-egg yolk diluent for 72 h. Progressive motility, live spermatozoa count and morphological abnormalities were evaluated every 12 h until 72 h of preservation. The colour, consistency and mass activity of fresh semen samples were found to be creamy white, medium and 3+ to 4+ (5+ scale), respectively. The average (mean+/-S.E.) volume (ml), pH and spermatozoa concentration (10(6) ml(-1)) of fresh semen samples were found to be 0.6+/-0.01, 6.8+/-0.03 and 425+/-48, respectively. Progressive motility and live spermatozoa count were found to be less than 30% (P<0.01) after 48 h of storage. Head (P<0.05), midpiece (P<0.05), tail (P<0.01) and total (P<0.01) abnormalities were found to be increased significantly over the time of storage. It was observed that progressive motility and live spermatozoa count remained above 30% and 40%, respectively, until 36 h of storage. Simultaneously the percentage of morphologically abnormal spermatozoa was found to be significantly low until 36 h of storage. The results indicate that it is possible to preserve mithun spermatozoa at refrigeration temperature in tris-egg yolk diluent, which can be further used for artificial insemination within 36 h of storage.


Assuntos
Refrigeração/veterinária , Ruminantes/fisiologia , Preservação do Sêmen/veterinária , Sêmen/fisiologia , Animais , Masculino , Preservação do Sêmen/métodos , Temperatura , Fatores de Tempo
13.
Reprod Fertil Dev ; 18(6): 619-26, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16930508

RESUMO

The present study reports the pulsatile secretion of gonadotrophins and 17beta-oestradiol (OE2) on the day of oestrus and at the mid-luteal phase of the oestrous cycle in mithun (Bos frontalis). The frequency of luteinising hormone (LH) and follicle-stimulating hormone (FSH) pulses was found to be greater (P < 0.05) on the day of oestrus than at the mid-luteal phase. In contrast, the amplitude of the LH and FSH pulses was greater (P < 0.01) at the mid-luteal phase than on the day of oestrus. A synchronised (P < 0.01) LH and FSH secretion pattern was found only at the mid-luteal phase. A pulsatile secretion pattern for OE2 in the peripheral circulation was evident for both phases of the oestrous cycle. The frequency of the OE2 pulses did not differ significantly in different phases of the oestrous cycle. In contrast, the amplitude of the OE2 pulses and the basal OE2 concentration were found to be greater (P < 0.01) at the mid-luteal phase than on the day of oestrus. A synchronised (P < 0.01) LH and OE2 secretion pattern was observed in both phases of the oestrous cycle. In contrast, a synchronised (P < 0.05) FSH and OE2 secretion pattern was found only on the day of oestrus. In conclusion, a different pattern of LH and FSH secretion was observed in both phases of the oestrous cycle, mainly on the day of oestrus, which indicates a differential regulatory mechanism of LH and FSH release. In addition, as in cattle, OE2 exerts a positive feedback on LH and FSH release on the day of oestrus and on LH release at the mid-luteal phase of the oestrous cycle in mithun. Also, as in cattle, the greater basal plasma OE2 concentration and increased amplitude of OE2 pulses exert a negative feedback on FSH release at the mid-luteal phase of the oestrous cycle.


Assuntos
Estradiol/metabolismo , Ciclo Estral/fisiologia , Hormônio Foliculoestimulante/metabolismo , Hormônio Luteinizante/metabolismo , Ruminantes/fisiologia , Animais , Retroalimentação Fisiológica , Feminino , Periodicidade , Fatores de Tempo
14.
Gen Comp Endocrinol ; 149(2): 173-81, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16828092

RESUMO

The present investigation was designed to study the role of LH and prostaglandin F2alpha (PGF2alpha) on the development and regression of corpus luteum (CL) in the mithun estrous cycle. Blood samples were collected from jugular vein and PGF2alpha secretion was evaluated on the basis of peripheral 15-keto-13,14-dihydro-PGF2alpha (PGFM) concentration. The daily variations in plasma LH, PGFM, and progesterone (P4) concentrations throughout the estrous cycle were monitored in morning and evening blood samples. The variations in plasma LH, PGFM, and P4 concentrations during the early luteal phase were monitored in blood samples that were collected every 2 h until 120 h following the onset of estrus (Day 0). The pulsatile secretion patterns of plasma LH, PGFM and P4 during estrus (Day 1), mid-diestrus (Day 10), and luteolysis (Day 14) were assessed in blood samples that were collected every 15 min for 6h. In the estrous cycle, P4 concentration increased above basal level on day 6-7, peaked on day 10-12 and declined thereafter. Following estrus, a significant (P<0.01) gradual increase in P4 concentration was observed. LH concentration was found to be significantly (P<0.01) greater around estrus and it declined gradually (P<0.01) following estrus. In the estrous cycle, PGFM concentration increased above basal level on day 9-11, peaked on day 16-17, and declined thereafter. The frequency of LH pulses and basal LH concentration were found to be significantly (P<0.01) greater on day 1, but significantly (P<0.01) greater amplitude of LH pulses was found on day 10 and 14. The frequency of P4 and PGFM pulses was found to be significantly (P<0.01) greater on day 1. In contrast, the amplitude of P4 and PGFM pulses and basal P4 and PGFM concentrations were found to be significantly (P<0.01) greater on day 10 and 14. The results indicate that probably the early stages of CL development continued until day 5-6 of the estrous cycle and a fully functional CL existed approximately at the mid estrous cycle. Luteolysis probably started since day 11-13 of the cycle and completed before the onset of the next estrus. The elevated basal LH concentration along with frequent low amplitude LH pulses were probably required for the early stages of CL development. In contrast, the high amplitude LH pulses of lower frequency during the mid estrous cycle were either sufficient or not required for maintaining the luteal function. Whereas, PGF2alpha pulses of greater amplitude and elevated basal PGF2alpha concentration during the mid and late estrous cycle were probably responsible for luteolysis.


Assuntos
Bovinos/fisiologia , Corpo Lúteo/crescimento & desenvolvimento , Dinoprosta/fisiologia , Ciclo Estral/fisiologia , Hormônio Luteinizante/fisiologia , Animais , Ritmo Circadiano/fisiologia , Corpo Lúteo/fisiologia , Dinoprosta/análogos & derivados , Dinoprosta/sangue , Feminino , Hormônio Luteinizante/sangue , Progesterona/sangue , Fluxo Pulsátil
15.
Reprod Domest Anim ; 41(2): 162-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16519723

RESUMO

The objective of the present study was to establish the changes in plasma concentrations of LH, FSH, estradiol 17-beta (E2) and progesterone (P4), as well as to understand their temporal relationships during oestrus in mithun (Bos frontalis). The experiment was conducted on 11 mithuns during third or fourth postpartum oestrous cycle. Since oestrus onset the jugular vein blood samples were collected every 2 h for 72 and 96 h, respectively from the animals without and with standing heat. The LH, FSH, E2 and P4 concentrations were estimated in plasma. The P4 concentration was fluctuated throughout the oestrus period and the average P4 concentration was found significantly (p<0.05) lower on the day of oestrus onset. The multiple rises in LH and FSH concentrations above the basal level in spike like fashion were observed throughout the oestrus period irrespective of the occurrence of standing heat. A significant (p<0.01) gradual increase in the average daily E2 concentration was observed till day 2 following oestrus onset irrespective of the occurrence of standing heat. A significant (p<0.05) simultaneous increase in LH, FSH and E2 concentrations and a transient increase in P4 concentration at approximately the time of standing heat onset were observed. During investigation a definite temporal coupling between LH and FSH rises was absent throughout the oestrus period. The results suggest that (1) the multiple short-duration low-amplitude LH and FSH surges during oestrus may be crucial for the final maturation of ovulatory follicle and subsequent ovulation in mithun; (2) a differential mechanism for controlling LH and FSH secretions probably exists in mithun.


Assuntos
Bovinos/fisiologia , Estradiol/sangue , Estro/sangue , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Progesterona/sangue , Animais , Bovinos/sangue , Estro/fisiologia , Feminino , Fatores de Tempo
16.
Theriogenology ; 64(9): 2010-21, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15950273

RESUMO

The objective of the present study was to establish the profiles of luteinising hormone (LH), follicle stimulating hormone (FSH), estradiol 17beta (E2) and progesterone (P4) secretion and their interrelationships during the natural estrous cycle of mithun (Bos frontalis). Daily blood samples were collected from second or third postpartum estrous cycles for determination of plasma concentrations of LH, FSH, E2 and P4. Concentration of P4 was found to be lowest on the day of estrus. It increased following estrus, attained the highest concentration on day 11 and decreased thereafter. Concentrations of LH and FSH varied significantly (p<0.01) during the first and last 6 days of the cycle and their variations were found to be synchronised. Both LH and FSH attained a biphasic peak during the estrous cycle. This biphasic peak lasted on from day -5 to day 3 of the cycle. The variations in maximum LH and FSH concentrations of both the phases did not differ significantly. During the entire estrous cycle, the E2 concentrations attained either one peak or two peaks. The first peak, approximately on day 4 before estrus was common in all animals. One additional peak was found on the day of estrus in 45% animals. A significant (p<0.01) negative relationship was found between P4 and, LH and FSH during the first and last 6 days of cycle. But a significant (p

Assuntos
Ciclo Estral/fisiologia , Hormônios/fisiologia , Ruminantes/fisiologia , Animais , Bovinos , Estradiol/sangue , Retroalimentação Fisiológica , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Progesterona/sangue
18.
Comput Nurs ; 15(1): 30-3; quiz 34-6, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9014391

RESUMO

The contractual process for the purchase of a health-care facility information system is a major endeavor for today's informatics practitioners as more facilities purchase information solution from vendors rather than producing proprietary systems. The goal of the contractual process is not simply to protect either party from future litigation but to produce a clearly understood document that outlines the duties and responsibilities of both the organization and the vendor. This document should anticipate and set forth contingencies for problems that may arise in the future. Guidelines are offered to assist nurses who are members of the acquisition team better understand the contract review process.


Assuntos
Serviços Contratados/normas , Sistemas de Informação Hospitalar/organização & administração , Negociação , Serviços Contratados/legislação & jurisprudência , Educação Continuada em Enfermagem , Software , Estados Unidos
19.
Clin Orthop Relat Res ; (279): 223-8, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1600659

RESUMO

The objective of this research was to investigate the load-bearing function of the fibula in relation to donor leg morbidity in patients who have had fibular resections. Biomechanical loading experiments were performed on ten anatomic specimens. Force transducers were mounted in place of resected tibial and fibular segments to allow load transmission to be measured. Load transmission through the fibula varied with ankle position. With the ankle at neutral position, the load distribution to the fibula averaged 7.12% of the total force transmitted through the tibia and fibula. Maximum loads occurred at full dorsiflexion and eversion. Resection of the proximal fibula results in a significant reduction of load through the distal fibular remnant. The values varied between 0.62% and 0.81% of the total force transmitted. When a cortex screw was introduced to anchor the distal fibula remnant to the tibia, the load distribution to the distal fibula remnant was partially restored with values ranging from 1.71% to 5.14% of the total force transmitted depending on the different ankle positions. These observations suggest that more consideration of the loading characteristics of the fibula should be taken into account in planning resection operations.


Assuntos
Fíbula/fisiologia , Fenômenos Biomecânicos , Fíbula/cirurgia , Fíbula/transplante , Humanos , Suporte de Carga
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