Maquiladora Employment Dynamics in Nuevo Laredo

ABSTRACT The Nuevo Laredo maquiladora sector has grown enormously during the last two decades. The short‐term time series characteristics of this portion of the regional economy are analyzed in an attempt to quantify the trends underlying this remarkable performance. Parameter estimation is accomplished via linear transfer function (LTF) analysis. Data are drawn from the January 1990–December 2000 sample period. Empirical results indicate that real wage rates, maquiladora plants, U.S. industrial activity, and the real exchange rate of the peso play significant roles in determining month‐to‐month fluctuations in maquiladora employment. Furthermore, sub‐sample forecast simulation exercises are conducted as an additional means for verifying model reliability. Empirical results indicate that the forecasts generated with the LTF model are less accurate than those associated with a simple random walk procedure for twelve separate step‐length periods.     

Acute cortisol responses of lambs castrated and docked using rubber rings with or without a castration clamp

Objective To measure the plasma cortisol response in lambs castrated and docked by three different methods (ring castration and tail docking, ring and clamp castration and tail docking; ring and clamp castration and ring tail docking) for 4 h after treatment.
Design A physiological study with controls.
Procedure A rubber ring was applied to the scrotum. Then the castration clamp was placed, distal to the ring, on each spermatic cord such that there was no overlap of the crush lines.
Results There were no differences in the cortisol secretion of the lambs castrated and tail docked by the ring only and by the ring plus castration clamp methods. Using the castration clamp in addition to the ring on the tail had no effect on cortisol secretion.
Conclusions Using the castration clamp did not appear to reduce the cortisol response to ring castration and docking, as demonstrated elsewhere, because the areas of uncrushed tissue between the two castration clamp crush lines allowed nociception from ischemic scrotal tissue to be transmitted cranially via undamaged nerve fibers.     

Evidence of soft-mode quantum phase transitions in electron double layers

Inelastic light scattering by low-energy spin-excitations reveals three distinct configurations of spin of electron double layers in gallium arsenide quantum wells at even-integer quantum Hall states. The transformations among these spin states appear as quantum phase transitions driven by the interplay between Coulomb interactions and Zeeman splittings. One of the transformations correlates with the emergence of a spin-flip intersubband excitation at vanishingly low energy and provides direct evidence of a link between quantum phase transitions and soft collective excitations in a two-dimensional electron system.     

Biodiversity assessment and conservation strategies

The efficient representation of all species in conservation planning is problematic. Often, species distribution is assessed by dividing the land into a grid; complementary sets of grids, in which each taxon is represented at least once, are then sought. To determine if this approach provides useful surrogate information, species and higher taxon data for South African plants and animals were analyzed. Complementary species sets did not coincide and overlapped little with higher taxon sets. Survey extent and taxonomic knowledge did not affect this overlap. Thus, the assumptions of surrogacy, on which so much conservation planning is based, are not supported.     

Relationship between endometritis and oxidative stress in the follicular fluid and luteal function in the buffalo

In this study, alteration in the follicular fluid composition and luteal function was investigated in the buffalo with endometritis. Genitalia were classified into cytological and purulent endometritis on the basis of polymorphonuclear cell cut off while non‐endometritis served as control (n = 10/group). In the follicular phase, the number of surface follicles was counted, diameter of the largest follicle was measured and the follicular fluid was assayed for total protein, cholesterol, malondialdehyde (MDA), total antioxidant capacity (TAC), oestradiol (E₂) and progesterone (P₄). The P₄ content of corpus luteum during mid‐luteal phase was estimated by radioimmunoassay. Ovaries from the follicular phase of oestrous cycle showed no significant difference in the total number of surface follicles, size of the largest follicle and volume of follicular fluid in the buffaloes with and without endometritis (p > .05). However, the antral fluid of the largest follicle from the genitalia of buffalo with cytological and purulent endometritis showed a significant decrease in the concentration of total protein, cholesterol, TAC and E₂ and a significant increase in the concentration of MDA and P₄ (p < .05). The results indicated that there is an association between endometritis and decreased ovarian function.     

Evaluation of the sedative and clinical effects of xylazine,detomidine, medetomidine and dexmedetomidine in miniature donkeys

ABSTRACT

Aim: To evaluate the sedative and clinical effects of I/V xylazine, detomidine, medetomidine and dexmedetomidine in miniature donkeys.

Methods: Seven clinically healthy, male adult miniature donkeys with a mean age of 6 years and weight of 105?kg, were assigned to five I/V treatments in a randomised, cross-over design. They received either 1.1?mg/kg xylazine, 20?μg/kg detomidine, 10?μg/kg medetomidine, 5?μg/kg dexmedetomidine or saline, with a washout period of ≥7 days. The degree of sedation was scored using a 4-point scale by three observers, and heart rate (HR), respiration rate (RR), rectal temperature and capillary refill time (CRT) were recorded immediately before and 5, 10, 15, 30, 60, 90 and 120 minutes after drug administration.

Results: All saline-treated donkeys showed no sedation at any time, whereas the donkeys treated with xylazine, detomidine, medetomidine and dexmedetomidine had mild or moderate sedation between 5 and 60 minutes after treatment, and no sedation after 90 minutes. All animals recovered from sedation without complication within 2 hours. The mean HR and RR of saline-treated donkeys did not change between 0 and 120 minutes after administration, but the mean HR and RR of donkeys treated with xylazine, detomidine, medetomidine and dexmedetomidine declined between 5 and 60 minutes after drug administration. The mean rectal temperature of all treated donkeys did not change between 0 and 120 minutes after administration. The CRT for all donkeys was ≤2 seconds at all times following each treatment.

Conclusions and clinical relevance: Administration of xylazine at 1.1?mg/kg, detomidine at 20?μg/kg, medetomidine at 10?μg/kg and dexmedetomidine at 5?μg/kg resulted in similar sedation in miniature donkeys. Therefore any of the studied drugs could be used for sedation in healthy miniature donkeys.