A role for interaction of the RNA polymerase flap domain with the sigma subunit in promoter recognition

In bacteria, promoter recognition depends on the RNA polymerase sigma subunit, which combines with the catalytically proficient RNA polymerase core to form the holoenzyme. The major class of bacterial promoters is defined by two conserved elements (the -10 and -35 elements, which are 10 and 35 nucleotides upstream of the initiation point, respectively) that are contacted by sigma in the holoenzyme. We show that recognition of promoters of this class depends on the "flexible flap" domain of the RNA polymerase beta subunit. The flap interacts with conserved region 4 of sigma and triggers a conformational change that moves region 4 into the correct position for interaction with the -35 element. Because the flexible flap is evolutionarily conserved, this domain may facilitate promoter recognition by specificity factors in eukaryotes as well.     

A regional evaluation of chromium tripicolinate supplementation of diets fed to reproducing sows

A cooperative research study involving 353 litters was conducted at three stations to determine the effects of graded levels of supplemental Cr from chromium tripicolinate (CrPic) on reproductive performance of sows and preweaning performance of their pigs. Primiparous and multiparous sows were fed fortified corn-soybean meal diets with supplemental levels of 0, 200, 600, or 1,000 ppb Cr (as-fed basis). Each station used at least three of the supplemental Cr levels, with two of those levels being 0 and 200 ppb. Station effects were observed for sow gestation weight gain, lactation weight change, lactation feed intake, litter size at birth and weaning, and pig weight at birth and weaning (P = 0.001 to 0.087). Supplemental Cr increased the number of pigs born live per litter (9.49, 9.82, 10.94, and 10.07; quadratic, P = 0.05) and sow lactation weight change (-0.2, 0.8, -4.1, and -3.9 kg; linear, P = 0.01) but decreased individual birth weight of total pigs born (1.61, 1.57, 1.47, and 1.56 kg; quadratic, P = 0.10). Tissues were obtained from a subset of sows from one station after they had completed three parities on the study. The content of Cr in the adrenal gland (16.4, 20.0, 34.0, and 48.4 ppb), kidney (35.8, 56.4, 132.6, and 176.0 ppb), and liver (22.8, 37.4, 87.6, and 92.2 ppb) was increased linearly (P = 0.001 to 0.005) by increasing CrPic supplementation. The results suggest that the supplementation level that maximizes the biological response is above that currently allowed. Additionally, supplementation of Cr at 1,000 ppb (five times currently permitted supplementation levels) was not detrimental to sow performance, even when fed continuously for three parities. There may be merit to continued research to evaluate higher supplementation rates.     

Unconditional quantum teleportation

Quantum teleportation of optical coherent states was demonstrated experimentally using squeezed-state entanglement. The quantum nature of the achieved teleportation was verified by the experimentally determined fidelity Fexp = 0.58 +/- 0.02, which describes the match between input and output states. A fidelity greater than 0.5 is not possible for coherent states without the use of entanglement. This is the first realization of unconditional quantum teleportation where every state entering the device is actually teleported.     

Thermodynamics of calcite growth: baseline for understanding biomineral formation

The complexity of biomineralized structures suggests the potential of organic constituents for controlling energetic factors during crystal synthesis. Atomic force microscopy was used to investigate the thermodynamic controls on carbonate growth and to measure the dependence of step speed on step length and the dependence of critical step length on supersaturation in precisely controlled solutions. These data were used to test the classic Gibbs-Thomson relationship and provided the step edge free energies and free energy barriers to one-dimension nucleation for calcite. Addition of aspartic acid, a common component in biomineralizing systems, dramatically affected growth morphology and altered the magnitude of the surface energy.     

Long‐Term Outcome after Arthroscopic Debridement of Distal Phalanx Extensor Process Fragmentation in 13 Horses

Objective— To report long-term outcome after arthroscopic removal of fragmentation of the extensor process of the distal phalanx in horses.
Study Design— Case series.
Animals— Adult horses (n=13).
Methods— Medical records (2003–2004) of horses that had arthroscopic debridement of fragmentation of the extensor process of the distal phalanx were reviewed. Inclusion criteria included: lameness localized to the foot, fragmentation of the extensor process of the distal phalanx debrided arthroscopically, and a follow-up period of ≥4 years.
Results— Of the 13 horses, lameness was resolved in 11 (85%) initially but distal interphalangeal joint pain recurred in 2 (15%) within 1 year of surgery. Three (23%) other horses were retired because of lameness at other sites during the follow-up period resulting in 46% (6/13) being not lame and in full work after 4 years. Substantial changes were identified at surgery in the contralateral joint of 7 horses, even when fragments were only present unilaterally.
Conclusions— Arthroscopic debridement of fragmentation of the extensor process of the forelimb distal phalanx has a good short-term prognosis for resolution of lameness and return to work but a more guarded prognosis for long-term soundness.
Clinical Relevance— These results allow for more accurate prognostication preoperatively and may support early debridement of fragmentation of the extensor process of the distal phalanx.     

A method of investigating the effect of droplet size on pesticide collection by vegetation

A new technique is described which allows an estimation of the relative collection of insecticide on a crop, for three discrete droplet sizes simultaneously. Three droplet clouds, each consisting of a different chemical, were released along a line perpendicular to the wind. Subsequent chemical analysis of vegetation samples showed the relative efficiency of capture by any part of the plant as a function of the droplet size. The target vegetation and the micrometeorological conditions were the same for all three droplet clouds and thus did not mask the effects of droplet size. Initial results for a young crop of irrigated cotton are presented. The downwind distributions of chemical residues were in good agreement with a theoretical model published by Bache and Sayer.     

The theory of social forestry intervention: the state of the art in Asia

This study focuses on the major issues in current thinking about the theory of social forestry development in Asia. The first of these issues concerns the cause of deforestation. The governmental view is that deforestation is a gradual process driven by community-based factors, whereas the community view is that deforestation is a stochastic process driven by external, political-economic factors. The two explanations have different implications for where the problematique of social forestry is located — in the forest community or in the forest agency — and how, therefore, it is to be addressed.A second issue concerns how and when social forestry interventions are carried out. The concept of a window-of-opportunity for intervention reflects a widespread belief that it is importantwhen interventions are carried out — with both the costs and benefits of intervention increasing as it is timed earlier and decreasing as it is timed later. A key determinant of the best time for intervention is the receptivity of the forest agency and the broader society. The purpose of intervention is to strengthen receptivity and other factors conducive to change, to hasten extant processes of change, and to minimize the possibility of a reversal of direction.A third issue is whether the focus of social forestry intervention should be on state lands or on community lands. While there are logical reasons for either foci, the continuing vacillation between them suggests the lack of a theoretical perspective with sufficient breadth to encompass them both. Whatever the focus, attitudinal change within the forest agency is usually mandated in social forestry interventions, but it is rarely accompanied with intervention in the underlying power relations, reflecting a continuing difficulty in viewing the forest agency sociologically. This lack of sociological perspective also is seen in the tendency to focus on adding resources perceived to be in short supply, instead of removing institutional obstacles —including those within the forest agency — to the proper use of existing resources.The final issue involves the unintended consequences of social forestry intervention. These include redirection of the intervention as a result of bureaucratic resistance or negative feedback, and secondary consequences stemming from the dynamic responses by forests, forest communities, and forest agencies to changes in their relationship.     

Evaluation of cardiorespiratory and biochemical effects of ketamine‐propofol and guaifenesin‐ketamine‐xylazine anesthesia in donkeys (Equus asinus)

ObjectivesTo evaluate the cardiorespiratory and biochemical effects of ketamine-propofol (KP) or guaifenesin-ketamine-xylazine (GKX) anesthesia in donkeys.Study designProspective crossover trial.AnimalsEight healthy, standard donkeys, aged 10 ± 5 years and weighing 153 ± 23 kg.MethodsDonkeys were premedicated with 1.0 mg kg^?1 of xylazine (IV) in both treatments. Eight donkeys were administered ketamine (1.5 mg kg^?1) and propofol (0.5 mg kg^?1) for induction, and anesthesia was maintained by constant rate infusion (CRI) of ketamine (0.05 mg kg^?1 minute^?1) and propofol (0.15 mg kg^?1 minute^?1) in the KP treatment. After 10 days, diazepam (0.05 mg kg^?1) and ketamine (2.2 mg kg^?1) were administered for induction, and anesthesia was maintained by a CRI (2.0 mL kg^?1 hour^?1) of ketamine (2.0 mg mL^?1), xylazine (0.5 mg mL^?1) and guaifenesin (50 mg mL^?1) solution. Quality of anesthesia was assessed along with cardiorespiratory and biochemical measurements.ResultsAnesthetic induction took longer in GKX than in KP. The induction was considered good in 7/8 with KP and in 6/8 in GKX. Anesthetic recovery was classified as good in 7/8 animals in both treatments. Xylazine administration decreased heart rate (HR) in both treatments, but in KP the HR increased and was higher than GKX throughout the anesthetic period. Respiratory rate was higher in GKX than in KP. PaO₂ decreased significantly in both groups during the anesthetic period. Glucose concentrations [GLU] increased and rectal temperature and PCV decreased in both treatments. Arterial lactate [LAC] increased at recovery compared with all time points in KP. [GLU] and calcium were higher in GKX than in KP at recovery.Conclusion and clinical relevanceThese protocols induced significant hypoxemia but no other cardiorespiratory or metabolic changes. These protocols could be used to maintain anesthesia in donkeys, however, they were not tested in animals undergoing surgery.     

Sinoscopic Treatment of Rostral Maxillary and Ventral Conchal Sinusitis in 60 Horses

Objective— To evaluate the use of sinoscopy for detection and treatment of ventral conchal sinus (VCS) and/or rostral maxillary sinus (RMS) disease in horses.
Study Design— Case series
Animals— Horses (n=60) with suspected paranasal sinus disease.
Methods— Horses were evaluated by sinoscopy through a conchofrontal sinus (CFS) portal with ventral conchal bulla (VCB) fenestration. Other endoscopic sinus approaches and adjunctive diagnostic tests; oral examination, computed tomography, radiography, scintigraphy and endoscopic examination of the upper portion of the respiratory tract were used in some horses.
Results— The CFS approach permitted adequate observation of the RMS and VCS in 53 horses (88%). Hemorrhage caused by VCB fenestration prevented examination of the RMS and/or VCS in 12 horses (21%). Observation of lesions was possible in all horses diagnosed with neoplasia, sinus cysts, and progressive ethmoidal hematomas. Endoscopy of the paranasal sinuses was useful diagnostically in 82% of horses with primary sinusitis. Other diagnostic modalities were usually required to confirm a diagnosis of dental sinusitis.
Conclusions— Trephination into the CFS with VCB fenestration is a minimally invasive technique that provides consistent access to the RMS and VCS. It facilitates diagnosis of many sinus disorders and endoscopically guided treatment of many horses with sinus cysts and primary sinusitis, in combination with sinus lavage.
Clinical Relevance— Many diseases affecting the RMS and VCS can be diagnosed and resolved endoscopically using a CFS approach with VCB fenestration, thus avoiding the need for osteoplastic sinus surgery and its associated risks and complications.