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1.
J Intellect Disabil Res ; 68(1): 84-93, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37698385

RESUMEN

BACKGROUND: Motor control issues are common for people with intellectual disabilities (PWID), resulting in difficulties with basic activities of daily living, including eating. Mastication, which is crucial for digestion and overall health, is poorly understood in this population. PWID shows frailty similar to older people, highlighting the importance of comparing masticatory motor control with older adults. This study compared the neuromuscular control of the masticatory muscles in middle-aged, PWID and older adults. METHODS: A cross-sectional analytical design was used. During the mastication task of a carrot piece (2 cm in diameter and weighing 0.5 g), surface electromyography was used to record muscle activity patterns from the right and left masseter and temporalis muscles. Principal component analysis (PCA) was used to assess neuromuscular control. A z-score normalisation of the first component's variance from PCA to identify those individuals with altered neuromuscular control. A mixed ANOVA was performed to assess the interaction between principal components, groups and body composition. RESULTS: Thirty PWIDs (aged 35-55 years), middle-aged adults and 32 older adults were recruited. PWID and older adults showed decreased neuromuscular control of the masticatory muscles compared to middle-aged control adults (P < 0.05). PWID had the highest proportion of individuals with altered neuromuscular control of the masticatory muscle (53%) compared to older adults (19%) and middle-aged adults (0%) (P < 0.05). CONCLUSIONS: Our results indicate that PWID and older adults have reduced neuromuscular control compared to middle-aged adults. Notably, a significant proportion of the PWID showed altered masticatory muscle control compared to older adults. Further research is needed to explore the potential benefits of masticatory muscle training for PWID.


Asunto(s)
Discapacidad Intelectual , Abuso de Sustancias por Vía Intravenosa , Persona de Mediana Edad , Humanos , Anciano , Actividades Cotidianas , Estudios Transversales , Músculos Masticadores/fisiología
2.
J Intellect Disabil Res ; 67(7): 630-639, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37042218

RESUMEN

BACKGROUND: Alterations in oral health have a negative impact on the quality of life of persons with intellectual disabilities (PwIDs). Chewing is a process that influences and determines optimal oral health. However, little is known about how intellectual disability (ID) affects masticatory performance. This study aimed to analyse the differences in masticatory performance between young adults with IDs, young adults without IDs and older adults without IDs. METHODS: A cross-sectional analytical design was used. The masticatory performance was evaluated with a chewing gum validated instrument. In addition, the labial and tongue strength was assessed with the Iowa Oral Performance Instrument. We compared the masticatory performance between groups using one-way analysis of covariance. Body mass index, muscle mass, missing teeth, lip strength and tongue strength were included as separate covariates. A multivariate regression analysis was performed to identify which independent variables could explain masticatory performance in each group. RESULTS: Thirty-two PwIDs, 31 young adults without IDs and 32 older adults without IDs were recruited. PwIDs showed poorer masticatory performance compared with older adults (mean difference: -3.06, 95% confidence interval: -3.87 to -2.26) and healthy controls (mean difference: -2.38, 95% confidence interval: -3.19 to -1.57). The analysis of covariance showed significant difference between groups in the masticatory performance (F = 47.35, P < 0.001, ηp 2  = 0.507). Missing teeth (P < 0.001), right lip strength (P = 0.025) and tongue strength (P = 0.007) as covariables showed a significant interaction with the model. In the PwID group, lip strength and lack of teeth explained 58% of the variance in masticatory performance (R2  = 0.580, standard error = 1.12, P < 0.001). CONCLUSIONS: Persons with intellectual disabilities have a poorer masticatory performance than adults without IDs. Our findings indicate that the primary determinants of optimal masticatory function in PwIDs are the strength of the lip seal and the number of missing teeth.


Asunto(s)
Discapacidad Intelectual , Humanos , Adulto Joven , Anciano , Estudios Transversales , Labio , Calidad de Vida , Lengua/fisiología
3.
Animals (Basel) ; 10(11)2020 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-33114673

RESUMEN

Embryo transfer and the vitrification of embryos could be used for the conservation and recovery of endangered donkey breeds. It is important to develop techniques that optimize recovery rates and the cryotolerance of donkey embryos. This study evaluates factors affecting the recovery rate, quality, and diameter of embryos obtained from donor jennies as a starting point for the use of vitrification and embryo transfer in the conservation of the Andalusian donkey. A total of 100 embryos were recovered out of 124 estrous cycles (80.6%). The donor jenny affected the rates of positive flushings (PFR; p = 0.040) and embryo recovery (ERR; p < 0.05) as well as embryo quality (p = 0.004). ERR was also affected by the number of flushings (p < 0.001), donor age (p < 0.05), successive cycle within donor (p < 0.001), and jacks (p < 0.05). Number of flushings (p < 0.001) and jack (p < 0.05) had a significant effect on PFR, whereas the day of flushing influenced the developmental stage (p < 0.001), embryo quality (p < 0.05), and diameter of embryos (p < 0.001). The number of flushings significantly influenced the diameter (p = 0.038) and embryo developmental stage (p = 0.001), whereas the developmental stage was statistically different between herds (p = 0.020). The factors influencing the success of this assisted reproductive technique were donor jenny, donor age, successive cycle within donor, day of flushing, number of flushings, and jack. The identification of these key points is crucial to achieve a higher efficiency of embryo transfer and vitrification processes, before considering their application in the conservation of endangered donkey breeds.

4.
Anim Reprod Sci ; 208: 106126, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31405480

RESUMEN

The aim of this study was to compare the effect of three sugars and Equex paste in a freezing extender for donkey sperm cryopreservation. Ejaculates (n = 18) were collected from six Andalusian donkeys of proven fertility were pooled (two ejaculates per pool) and cryopreserved using a freezing extender containing three different sugars (glucose, fructose and sorbitol), with or without the addition of Equex paste. Sperm quality was assessed before and after freezing-thawing for motility, morphology, plasma membrane integrity, acrosome integrity and DNA integrity. The use of sorbitol in the freezing extender improved total and progressive sperm motility (P < 0.05) and amplitude of lateral head displacement (P < 0.01), but it reduced the values for other sperm motility variables compared with glucose (P < 0.001). The use of fructose resulted in a reduction in values for most CASA variables (P < 0.05), whereas addition of Equex paste did not have any beneficial effect on values for these variables (P > 0.05). Glucose was more effective in maintaining sperm morphology (P < 0.05), while there was no beneficial effect with the addition of Equex paste (P > 0.05). Supplementation of fructose and Equex paste in the freezing extender decreased plasma membrane integrity (P < 0.05) as compared with glucose, but there were no differences between treatments for acrosome and DNA integrity (P > 0.05), even after 24 h of incubation. The use of different sugar sources in the extender could affect the in vitro post-thaw quality of cryopreserved donkey spermatozoa, with sorbitol being an interesting alternative for improving the sperm quality. Results of the present study indicate the use of Equex paste could negatively affect post-thaw outcomes for sperm viability in this species.


Asunto(s)
Criopreservación/veterinaria , Crioprotectores/farmacología , Equidae/fisiología , Preservación de Semen/veterinaria , Espermatozoides/fisiología , Animales , ADN/química , Congelación , Masculino , Análisis de Semen , Preservación de Semen/métodos , Motilidad Espermática/fisiología
5.
Anim Reprod Sci ; 204: 31-38, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30902454

RESUMEN

The aim of this study was to assess the effect of different factors affecting vitrification success of donkey sperm: extender, sperm concentration, volume and storage vessel type. In Experiment 1, sucrose supplementations at 0.25 and 0.1 M were compared using two base extenders (containing or not egg-yolk); in Experiment 2, three sperm concentrations were assessed: 100, 200 or 300 million sperm/mL; and in Experiment 3, three different sperm volumes (100, 160 and 200 µL) and two different storage vessels (0.25 and 0.5 mL straws) were assessed. Sperm motility variables (CASA), plasma membrane and acrosome (evaluated under fluorescence microscopy) and sperm DNA integrity (flow cytometry) were evaluated after warming with comparisons of protocols. There was a greater total (55.7 ± 16.4%) and progressive (44.0 ± 11.5%) motility using the extender with egg-yolk and 0.1 M sucrose. There were no effects of sperm concentrations on vitrification results (P > 0.05). The 0.25 mL covered straw showed higher values than the 0.5 mL straw for total (50.0 ± 17.3% vs 2.0 ± 6.7%) and progressive (40.5 ± 14.9% vs 0.9 ± 1.5%) motility, plasma membrane (43.9 ± 14.4% vs 14.0 ± 16.4%) and acrosome integrity (51.5 ± 13.6% vs 28.0 ± 14.7%), respectively. In conclusion, values for donkey sperm quality variables after vitrification were greater using an extender containing egg-yolk and 0.1 M sucrose, at 300 million sperm/mL in 0.25 mL straws with outer covers.


Asunto(s)
Criopreservación/veterinaria , Equidae , Preservación de Semen/veterinaria , Sacarosa/farmacología , Vitrificación , Animales , Criopreservación/métodos , Crioprotectores/farmacología , Masculino , Análisis de Semen/veterinaria , Preservación de Semen/métodos , Motilidad Espermática/efectos de los fármacos
6.
Anim Reprod Sci ; 193: 201-208, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29699919

RESUMEN

The aim of this study was to evaluate the effect of different cooling rates on post-thaw quality of cryopreserved donkey spermatozoa. Eighteen ejaculates from six adult Andalusian donkeys (three ejaculates per donkey) were collected using an artificial vagina. Pooled semen samples (two ejaculates per pool) were divided into three aliquots, and frozen in Gent freezing extender using three different cryopreservation protocols (P): P1 (conventional slow freezing, as control): semen pre-cooled in an Equitainer for 2 h and frozen in liquid nitrogen (LN2) vapour; P2 (controlled pre-freeze cooling rate): semen pre-cooled at a controlled rate for 73 min and frozen in LN2 vapour; and P3 (rapid freezing) semen frozen immediately in LN2 vapour. After thawing at 37 °C for 30 s, semen samples were assessed for motility, morphology, acrosome and plasma membrane integrity; spermatozoa were also tested for DNA integrity. Significant (P < 0.01) differences were found between the cryopreservation protocols for all sperm parameters evaluated, except for DNA integrity. Semen samples frozen using P2 showed significantly (P < 0.01) higher values for sperm motility, morphology, sperm membrane integrity, and acrosome integrity. On the contrary, P3 reduced sperm motility (P < 0.01) and increased the percentage of spermatozoa with damaged plasma membrane (P < 0.001). In our study, we demonstrated that the sperm of Andalusian donkey is particularly sensitive to the cooling rate used before freezing. Furthermore, Andalusian donkey semen can be successfully cryopreserved using controlled cooling rates combined with freezing in LN2 vapour.


Asunto(s)
Criopreservación/métodos , Equidae , Análisis de Semen , Preservación de Semen/métodos , Animales , Frío , Criopreservación/veterinaria , Crioprotectores/farmacología , Congelación , Masculino , Semen/efectos de los fármacos , Semen/fisiología , Análisis de Semen/veterinaria , Preservación de Semen/veterinaria , Espermatozoides/citología , Espermatozoides/efectos de los fármacos
8.
Haemophilia ; 23(6): e497-e503, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28891593

RESUMEN

INTRODUCTION: Repeated haemarthrosis is widely accepted as the triggering cause of synovitis and haemophilic arthropathy. A first-line treatment of chronic synovitis is radiosynoviorthesis (RS). The aim of this study was to evaluate the RS effects on the progression of arthropathy and on a reduction in bleeding in patients with haemophilia. METHODS: An observational-retrospective study was performed. Bleeding episodes in the 12 months following and in the 12 months preceding RS was compared. The arthropathy was clinically and radiologically analysed by age range, joint and subject, comparing those undergoing RS (Radiosynoviorthesis Group, RSG) against those not undergoing this treatment (Non-Radiosynoviorthesis Group, Non-RSG). RESULTS: One hundred and seventy-four RS were performed in 71 patients (90 Y in Knees and 186 Re in elbows/ankles/shoulder). RS resulted in significant reduction in bleeding (582 preintervention and 168 postintervention, P < .001). In general, the level of arthropathy measured clinically and radiologically was greater with age increase in both groups (RSG and Non-RSG), especially in the 25-40 age range. A significant increase (P < .05) in the progression of arthropathy was also observed, both globally by patient and specifically for each joint, in non-RSG and RSG group. CONCLUSION: RS is an effective method to reduce the number of haemarthrosis episodes in chronic synovitis. Moreover, RS can positively affect arthropathy by slowing down its progression. However, the results obtained suggest that arthropathy may be conditioned by the subject's age, regardless of whether or not the joint has undergone RS.


Asunto(s)
Hemartrosis/terapia , Artropatías/terapia , Radioisótopos/uso terapéutico , Renio , Sinovectomía/métodos , Radioisótopos de Itrio/uso terapéutico , Adolescente , Adulto , Articulación del Tobillo/patología , Articulación del Tobillo/efectos de la radiación , Articulación del Tobillo/cirugía , Progresión de la Enfermedad , Articulación del Codo/patología , Articulación del Codo/efectos de la radiación , Articulación del Codo/cirugía , Hemartrosis/etiología , Hemofilia A/complicaciones , Humanos , Artropatías/etiología , Persona de Mediana Edad , Estudios Retrospectivos , Articulación del Hombro/patología , Articulación del Hombro/efectos de la radiación , Articulación del Hombro/cirugía , Sinovitis/etiología , Sinovitis/terapia , Resultado del Tratamiento , Adulto Joven
9.
Haemophilia ; 23(1): e18-e24, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27928870

RESUMEN

INTRODUCTION: Alterations in the musculoskeletal system, especially in the lower limbs, limit physical activity and affect balance and walking. Postural impairments in haemophilic preteens could increase the risk of bleeding events and deteriorate the physical condition, promoting the progression of haemophilic arthropathy. AIM: This study aims to evaluate static postural balance in haemophilic children, assessed by means of the Wii Balance Board® (WBB). METHODS: Nineteen children with haemophilia and 19 without haemophilia aged 9-10 years, have participated in this study. Postural balance was assessed by performing four tests, each one lasting 15 s: bipodal eyes open (BEO), bipodal eyes closed (BEC), monopodal dominant leg (MD) and monopodal non-dominant leg (MND). Two balance indices, standard deviation of amplitude (SDA) and standard deviation of velocity (SDV) were calculated in the anterior-posterior (AP) and medial-lateral (ML) directions. RESULTS: Index values were higher in haemophilic group and the differences were statistically significant (P < 0.05) in only six (SDAAP in BEO, BEC and MD conditions, SDAML in BEO, SDVAP in BEO and SDVML in MND condition) of 16 parameters analysed. CONCLUSION: Tests performed indicate a poorer static postural balance in the haemophilic cohort compared to the control group. Accordingly, physiotherapy programmes, physical activity and sports should be designed to improve the postural balance with the aim of preventing joint deterioration and improving quality of life.


Asunto(s)
Hemofilia A/diagnóstico , Hemofilia A/fisiopatología , Juegos de Video , Niño , Femenino , Humanos , Masculino , Equilibrio Postural/fisiología , Calidad de Vida
10.
Reprod Fertil Dev ; 28(12): 1990-1998, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26129907

RESUMEN

The aim of this study was to compare the effect of two semen extenders and four permeating cryoprotectants on post-thaw sperm quality of Andalusian donkeys. First, 32 ejaculates were pooled, split and frozen in either Gent B or INRA 96 with egg yolk and glycerol. Second, 12 pooled semen samples were simultaneously frozen in Gent B (glycerol) or Gent A containing ethylene glycol (EG; 1 or 1.5%) or dimethyl sulfoxide (DMSO; 1.5 or 2%). Finally, nine pooled samples were simultaneously cryopreserved in Gent A containing 1% EG (as control), dimethylformamide (DMFA; 1 or 2.5%) or a combination of 1% EG and 1.5% DMFA. Gent B yielded a higher (P<0.01) post-thaw sperm motility than modified INRA96. EG 1% increased the sperm membrane integrity (P<0.001), whereas DMSO affected sperm motility and membrane integrity (P<0.001). DMFA 2.5% yielded higher (P<0.001) values for sperm motility and membrane integrity. We concluded that Gent B improves in vitro post-thaw sperm quality of donkey spermatozoa, but the replacement of glycerol with 1% EG or 2.5% DMFA increased sperm protection against cryodamage. The use of DMSO for freezing donkey semen was unsuccessful and a toxic effect is suspected. These extenders should be included in the pre-freeze test for each donkey.


Asunto(s)
Criopreservación , Crioprotectores , Preservación de Semen , Espermatozoides/citología , Animales , Dimetilsulfóxido , Dimetilformamida , Equidae , Glicerol , Masculino , Motilidad Espermática
11.
Anim Reprod Sci ; 146(1-2): 79-88, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24602506

RESUMEN

The main aim of this study was to evaluate the efficacy of two commercially available liquid stallion semen extenders for the preservation of Andalusian donkey semen at 5°C for up to 72h, and to evaluate the effect of amino acid addition on sperm quality of cooled donkey semen. In addition, this study investigated the effect of seasons on semen characteristics of Andalusian jackasses. Throughout a year, 50 ejaculates were collected from ten adult donkeys and a complete semen evaluation was performed immediately after collection. In Experiment 1, semen samples (n=32) were pooled, divided into two aliquots, and cooled in either Gent(®) A or INRA 96(®). In Experiment 2, pooled semen samples (n=9) were cooled in Gent A(®) supplemented with 0 (as control), 20, 40, or 60mM for each glutamine, proline, or taurine. Fresh semen and chilled samples were assessed for sperm motility, morphology, acrosome integrity, and plasma membrane integrity. Sperm motility variables were greater (P<0.05) in Gent(®) A than in INRA 96(®). The presence of glutamine, proline, or taurine in Gent(®) A improved (P<0.001) the motility of Andalusian donkey spermatozoa. Differences (P<0.05) in some sperm variables were observed among seasons. In conclusion, Gent(®) A maintained sperm motility characteristics after 72h of cold storage to a greater extent than INRA 96(®). Moreover, motility was greater when Gent(®) A supplemented at different concentrations of amino acids than Gent(®) A with no supplementation. An effect of seasons on the semen quality of the Andalusian donkey was demonstrated.


Asunto(s)
Aminoácidos/farmacología , Equidae/fisiología , Análisis de Semen/veterinaria , Preservación de Semen/veterinaria , Espermatozoides/efectos de los fármacos , Espermatozoides/fisiología , Aminoácidos/química , Animales , Masculino , Motilidad Espermática
12.
Animal ; 8(2): 308-15, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24284302

RESUMEN

The aim of this study was to determine the effect of single layer centrifugation (SLC) using Androcoll-E-Large on donkey sperm quality parameters after 24 h of cool-storage. Ejaculates were collected from Andalusian donkeys and then cooled at 5°C. SLC was carried out after 24 h of cool-storage using Androcoll-E-Large. In the first experiment, all sperm parameters assessed (total and progressive sperm motility, viability, sperm morphology and sperm kinematics VCL, VSL, VAP, LIN, STR, WOB, ALH and BCF) were statistically compared between semen samples processed or not with Androcoll-E-Large. Significant differences (P<0.05) were found between SLC-selected and unselected semen samples for all parameters assessed, obtaining better results after SLC. In the second experiment, semen samples were classified in two groups according to their sperm progressive motility (PM) before SLC. Then, the increments obtained in semen quality parameters after SLC were compared between groups. No significant differences were found between groups, indicating that SLC improved the sperm quality parameters of entire set of semen samples processed with independence to their original PM. In conclusion, SLC with Androcoll-E-Large can be used in donkeys, increasing the sperm quality of cooled-stored donkey semen doses after 24 h of cool storage.


Asunto(s)
Centrifugación/métodos , Equidae/fisiología , Espermatozoides/citología , Espermatozoides/fisiología , Análisis de Varianza , Animales , Fenómenos Biomecánicos , Supervivencia Celular/fisiología , Frío , Masculino , Motilidad Espermática/fisiología , Conservación de Tejido/métodos , Conservación de Tejido/veterinaria
13.
Anim Reprod Sci ; 143(1-4): 64-71, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24210876

RESUMEN

Sperm quality has an important role in determining fertility. The aims of this study were to compare the conventional sperm parameters, plus the characteristics of the motility patterns of the different sperm subpopulations, of donkey donors with different fertility level, and to determine their relationships to fertility. Thirty ejaculates from 6 Andalusian donkeys were assessed for gel-free volume, pH, sperm concentration, motility and morphology. The fertility of donkeys was classified on the basis of pregnancy rates per cycle, where donkeys with a per cycle pregnancy rate ≥60% were considered to be "fertile" (n=3) and those with a per cycle pregnancy rate <40% were categorized to be "sub-fertile" (n=3). Significant differences (P<0.001) between the "fertile" and the "sub-fertile" group were found for total and progressive motility, and for straight line velocity. Sperm variables associated (P<0.05) with an increase in percent pregnant per cycle included total motility (r=0.37), progressive motility (r=0.53), curvilinear velocity (r=0.44), straightness (r=0.39), beat cross frequency (r=0.44), and gel-free volume (r=0.53). Four sperm subpopulations (sP) were identified in fresh semen: sP1 (slow and non-progressive spermatozoa, 20%), sP2 (moderately slow but progressive spermatozoa, 71.2%), sP3 (highly active but non-progressive spermatozoa, 2.9%), and sP4 (highly active and progressive spermatozoa, 5.9%). The lowest percentage (3.1%; P<0.001) of sP4 spermatozoa was observed in the "sub-fertile" group. Three of the sperm subpopulations were related (P<0.05) to fertility (sP2, r=0.54; sP3, r=0.45; sP4, r=0.56). In conclusion, we were able to relate the fertility of donkeys with in vitro measures of sperm motility using computer-assisted sperm analysis techniques.


Asunto(s)
Equidae/fisiología , Fertilidad/fisiología , Semen/fisiología , Motilidad Espermática , Animales , Eyaculación , Femenino , Masculino , Embarazo , Índice de Embarazo , Estudios Retrospectivos , Análisis de Semen
14.
Theriogenology ; 79(7): 1100-9, 2013 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-23473870

RESUMEN

The aims of this study were to (1) identify sperm subpopulations with specific motion characteristics in fresh Andalusian donkey ejaculates; (2) evaluate the effects of individual donkey and ejaculates within the same donkey on the distribution of the subpopulations found; and (3) explore the relationship between the age and the body weight of donkey donors, the sperm quality parameters, and the sperm subpopulations structure. Sixty ejaculates from 12 Andalusian donkeys (five ejaculates per donkey), ranging in age from 4 to 15 years, were collected. Immediately after collection, sperm characteristics (volume, sperm concentration, objective sperm motility, and sperm morphology) were assessed. Donkeys were evaluated for body weight. Significant (P < 0.05) correlations were established between the body weight of the donkeys and the pH (r = -0.52), sperm motility (percentage of motile spermatozoa: r = -0.31; percentage of progressive motile spermatozoa: r = -0.34), and total sperm abnormalities (r = 0.38). The correlations of the age with the measures of semen quality were low and not significant (P > 0.05). A multivariate clustering procedure separated 65,342 motile spermatozoa into four subpopulations: subpopulation 1, consisting of slow and nonprogressive spermatozoa (15.4%), subpopulation 2, consisting of moderately slow but progressive spermatozoa (35.9%), subpopulation 3, consisting of highly active but nonprogressive spermatozoa (18.5%), and subpopulation 4, consisting of highly active and progressive spermatozoa (30.2%). The distribution of these subpopulations varied significantly (P < 0.05) according to several parameters such as the individual donkey, the ejaculate of the same donkey, the total motility, and the overall sperm concentration. Our results show the existence of four well-defined motile sperm subpopulations in Andalusian donkey ejaculates, and suggest a high heterogeneity in the ejaculate structure in donkey. The relationship between the distribution of the sperm subpopulations and individual donkey, total motility, and sperm concentration shows that the spermatozoa of each have different motility patterns. However, the proportions of sperm subpopulations in the ejaculates did not vary with age and body weight. Finally, the study of discrete subpopulations of motile spermatozoa could lead to a substantial increase in information acquired during donkey semen analysis.


Asunto(s)
Equidae/fisiología , Análisis de Semen/veterinaria , Motilidad Espermática , Factores de Edad , Animales , Peso Corporal , Equidae/anatomía & histología , Masculino
15.
Phys Rev Lett ; 109(24): 241602, 2012 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-23368304

RESUMEN

Using the method of maximal cuts, we construct the complete D-dimensional integrand of the five-loop four-point amplitude of N=4 super-Yang-Mills theory, including nonplanar contributions. In the critical dimension where this amplitude becomes ultraviolet divergent, we present a compact explicit expression for the nonvanishing ultraviolet divergence in terms of three vacuum integrals. This construction provides a crucial step towards obtaining the corresponding amplitude of N=8 supergravity required to resolve the general ultraviolet behavior of supergravity theories.

16.
Phys Rev Lett ; 103(8): 081301, 2009 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-19792710

RESUMEN

We describe the construction of the complete four-loop four-particle amplitude of N=8 supergravity. The amplitude is ultraviolet finite, not only in four dimensions, but in five dimensions as well. The observed extra cancellations provide additional nontrivial evidence that N=8 supergravity in four dimensions may be ultraviolet finite to all orders of perturbation theory.

17.
Phys Rev Lett ; 98(16): 161303, 2007 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-17501410

RESUMEN

We construct the three-loop four-point amplitude of N=8 supergravity using the unitarity method. The amplitude is ultraviolet finite in four dimensions. Novel cancellations, not predicted by traditional superspace power-counting arguments, render its degree of divergence in D dimensions no worse than that of N=4 super-Yang-Mills theory--a finite theory in four dimensions. Similar cancellations can be identified at all loop orders in certain unitarity cuts, suggesting that N=8 supergravity may be a perturbatively finite theory of quantum gravity.

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