Baseline,diurnal variations,and stress-induced changes of stress hormones in three captive beluga whales,Delphinapterus leucas

Concentrations of plasma adrenocorticotropic hormone (ACTH), cortisol, and aldosterone were investigated in three adult beluga whales (Delphinapterus leucas), held in a large outdoor public aquarium exhibit. The purpose of this study was to evaluate resting concentrations of these hormones and associated diurnal variations with routine interactions and medical procedures. Resting blood samples were collected voluntarily from the ventral fluke veins at predetermined times of the day to evaluate diurnal changes in analyte concentrations. In addition, hematology and serum chemistry analyses were performed to monitor health status and evaluate changes related to physical exam procedures. Analogous sampling was conducted during out-of-water physical examinations and before and after wading-contact sessions (WCS). Baseline stress hormone concentrations (± SD) were as follows: plasma ACTH (8.41 ± 5.8 pg/mL), serum cortisol (1.80 ± 0.71 g/dL), and serum aldosterone (11.42 ± 5.5 pg/mL). Plasma ACTH and cortisol concentrations were consistently higher in early morning than evening, while aldosterone was higher in the evening. All stress-related hormones were significantly elevated during physical examination. Plasma ACTH concentrations were most increased, 5–10-fold, during physical examination, whereas cortisol and aldosterone showed 2–4-fold elevations. Stress response analytes measured during the WCS did not differ significantly from baseline concentrations.     

Evaluation of secondary amide replacements in a series of CCR5 antagonists as a means to increase intrinsic membrane permeability. Part 1: Optimization of gem-disubstituted azacycles

Replacement of a secondary amide with an N-acyl or N-sulfonyl gem-disubstituted azacyle in a series of CCR5 antagonists led to the identification of compounds with excellent in vitro HIV antiviral activity and increased intrinsic membrane permeability.     

Are there differences in brain morphometry between twins and unrelated singletons? A pediatric MRI study

Twins provide a unique capacity to explore relative genetic and environmental contributions to brain development, but results are applicable to non‐twin populations only to the extent that twin and singleton brains are alike. A reason to suspect differences is that as a group twins are more likely than singletons to experience adverse prenatal and perinatal events that may affect brain development. We sought to assess whether this increased risk leads to differences in child or adolescent brain anatomy in twins who do not experience behavioral or neurological sequelae during the perinatal period. Brain MRI scans of 185 healthy pediatric twins (mean age = 11.0, SD = 3.6) were compared to scans of 167 age‐ and sex‐matched unrelated singletons on brain structures measured, which included gray and white matter lobar volumes, ventricular volume, and area of the corpus callosum. There were no significant differences between groups for any structure, despite sufficient power for low type II (i.e. false negative) error. The implications of these results are twofold: (1) within this age range and for these measures, it is appropriate to include healthy twins in studies of typical brain development, and (2) findings regarding heritability of brain structures obtained from twin studies can be generalized to non‐twin populations.     

Proteomic changes in maize roots after short-term adjustment to saline growth conditions

It is of fundamental importance to understand adaptation processes leading to salt resistance. The initial effects on maize roots in the first hour after the adjustment to saline conditions were monitored to elucidate initial responses. The subsequent proteome change was monitored using a 2‐D proteomic approach. We found several new salt‐inducible proteins, whose expression has not been previously reported to be modulated by salt. A set of phosphoproteins in maize was detected but only ten proteins were phosphorylated and six proteins were dephosphorylated after the application of 25 mM NaCl for 1 h. Some of the phosphorylated maize proteins such as fructokinase, UDP‐glucosyl transferase BX9, and 2‐Cys‐peroxyredoxine were enhanced, whereas an isocitrate‐dehydrogenase, calmodulin, maturase, and a 40‐S‐ribosomal protein were dephosphorylated after adjustment to saline conditions. The initial reaction of the proteome and phosphoproteome of maize after adjustment to saline conditions reveals members of sugar signalling and cell signalling pathways such as calmodulin, and gave hint to a transduction chain which is involved in NaCl‐induced signalling. An alteration of 14‐3‐3 proteins as detected may change plasma membrane ATPase activity and cell wall growth regulators such as xyloglucane endotransglycosylase were also found to be changed immediately after the adjustment to salt stress.     

Deep intra-uterine artificial inseminations using cryopreserved spermatozoa in beluga (Delphinapterus leucas)

Artificial insemination (AI) with liquid-stored spermatozoa and sperm cryopreservation using directional freezing (DF) have been successful in the beluga. This study built on this foundation to develop a deep intra-uterine AI technique with frozen-thawed semen in beluga. Forty-two ejaculates from one male were cryopreserved using DF technology and subsequently used for 10 insemination attempts with seven females. Percentage pre- and post-thaw progressive motility and viability were (mean ± SD) 73.0 ± 12.2, 38.4 ± 8.8, 88.0 ± 0.1, and 59.3 ± 15.7%, respectively. A series of GnRH injections (3 x 250 μg, IV, 1.5 to 2 h apart) were used to induce ovulation, once a growing follicle >2.5 cm in diameter was visualized via trans-abdominal ultrasonography. Artificial insemination was performed at 30.1 ± 3.8 h post-initial GnRH injection with semen deposited in the uterine horn, 92.6 ± 16.2 cm beyond the genital opening using a flexible endoscope. The external cervical os (cEOS) was located beyond a series of 5 to 10 vaginal rings, 44.8 ± 9.3 cm from the external genital opening. The internal bifurcation of the uterus was 27 ± 6.8 cm beyond the cEOS. Ovulation occurred at 8.5 ± 7.6 h post-AI. Two of 10 inseminations (20%) resulted in pregnancy. The first pregnancy resulted in twins; both calves were born 442 d after AI, with one surviving. The second pregnancy is ongoing. These findings represent the first successful application of AI using frozen-thawed semen in beluga, and are important examples of how assisted reproductive technologies can provide tools for the global management of threatened species.     

Triggers and maintenance of multiple shifts in the state of a natural community

Ecological communities can undergo sudden and dramatic shifts between alternative persistent community states. Both ecological prediction and natural resource management rely on understanding the mechanisms that trigger such shifts and maintain each state. Differentiating between potential mechanisms is difficult, however, because shifts are often recognized only in hindsight and many occur on such large spatial scales that manipulative experiments to test their causes are difficult or impossible. Here we use an approach that focuses first on identifying changes in environmental factors that could have triggered a given state change, and second on examining whether these changes were sustained (and thus potentially maintained the new state) or transitory (explaining the shift but not its persistence). We use this approach to evaluate a community shift in which a benthic marine species of filter feeding sea cucumber (Pachythyone rubra) suddenly came to dominate subtidal rocky reefs that had previously supported high abundances of macroalgae, persisted for more than a decade, then abruptly declined. We found that a sustained period without large wave events coincided with the shift to sea cucumber dominance, but that the sea cucumbers persisted even after the end of this low wave period, indicating that different mechanisms maintained the new community. Additionally, the period of sea cucumber dominance occurred when their predators were rare, and increases in the abundance of these predators coincided with the end of sea cucumber dominance. These results underscore the complex nature of regime shifts and illustrate that focusing separately on the causes and maintenance of state change can be a productive first step for analyzing these shifts in a range of systems.