Goats show higher behavioural flexibility than sheep in a spatial detour task.

The ability to adapt to changing environments is crucial for survival and has evolved based on socio-ecological factors. Goats and sheep are closely related, with similar social structures, body sizes and domestication levels, but different feeding ecologies, i.e. goats are browsers and sheep are grazers. We investigated whether goats' reliance on more patchily distributed food sources predicted an increased behavioural flexibility compared to sheep. We tested 21 goats and 28 sheep in a spatial A-not-B detour task. Subjects had to navigate around a straight barrier through a gap at its edge. After one, two, three or four of these initial A trials, the gap was moved to the opposite end and subjects performed four B trials. Behaviourally more flexible individuals should move through the new gap faster, while those less behaviourally flexible should show greater perseveration. While both species showed an accuracy reduction following the change of the gap position, goats recovered from this perseveration error from the second B trial onwards, whereas sheep did so only in the fourth B trial, indicating differences in behavioural flexibility between the species. This higher degree of flexibility in goats compared to sheep could be linked to differences in their foraging strategies.

A novel integrin specificity exemplified by binding of the alpha v beta 5 integrin to the basic domain of the HIV Tat protein and vitronectin.

Several studies have addressed the interaction of the HIV Tat protein with the cell surface. Our analysis of the cell attachment-promoting activity of Tat and peptides derived from it revealed that the basic domain of Tat, not the arg-gly-asp (RGD) sequence, is required for cell attachment to Tat. Affinity chromatography with Tat peptides and immunoprecipitation with various anti-integrin antibodies suggest that the vitronectin-binding integrin, alpha v beta 5, is the cell surface protein that binds to the basic domain of Tat. The Tat basic domain contains the sequence RKKRRQRRR. A related sequence, KKQRFRHRNRKG, present in the heparin-binding domain of an alpha v beta 5 ligand, vitronectin, also bound alpha v beta 5 in affinity chromatography and, in combination with an RGD peptide, was an inhibitor of cell attachment to vitronectin. The alpha v beta 5 interaction with these peptides was not solely due to high content of basic amino acids in the ligand sequences; alpha v beta 5 did not bind substantially to peptides consisting entirely of arginine or lysine, whereas a beta 1 integrin did bind to these peptides. The interaction of alpha v beta 5 with Tat is atypical for integrins in that the binding to Tat is divalent cation independent, whereas the binding of the same integrin to an RGD-containing peptide or to vitronectin requires divalent cations. These data define an auxiliary integrin binding specificity for basic amino acid sequences. These basic domain binding sites may function synergistically with the binding sites that recognize RGD or equivalent sequences.

Proximal cretaceous-tertiary boundary impact deposits in the Caribbean.

Trace element, isotopic, and mineralogic studies indicate that the proposed impact at the Cretaceous-Tertiary (K-T) boundary occurred in an ocean basin, although a minor component of continental material is required. The size and abundance of shocked minerals and the restricted geographic occurrence of the ejecta layer and impact-wave deposits suggest an impact between the Americas. Coarse boundary sediments at sites 151 and 153 in the Colombian Basin and 5- to 450-meter-thick boundary sediments in Cuba may be deposits of a giant wave produced by a nearby oceanic impact. On the southern peninsula of Haiti, a approximately 50-centimeter-thick ejecta layer occurs at the K-T boundary. This ejecta layer is approximately 25 times as thick as that at any known K-T site and suggests an impact site within approximately 1000 kilometers. Seismic reflection profiles suggest that a buried approximately 300-km-diameter candidate structure occurs in the Colombian Basin.

The fall, recovery, orbit, and composition of the Tagish Lake meteorite: a new type of carbonaceous chondrite.

The preatmospheric mass of the Tagish Lake meteoroid was about 200,000 kilograms. Its calculated orbit indicates affinity to the Apollo asteroids with a semimajor axis in the middle of the asteroid belt, consistent with a linkage to low-albedo C, D, and P type asteroids. The mineralogy, oxygen isotope, and bulk chemical composition of recovered samples of the Tagish Lake meteorite are intermediate between CM and CI meteorites. These data suggest that the Tagish Lake meteorite may be one of the most primitive solar system materials yet studied.

OSIRIS-REx Contamination Control Strategy and Implementation.

OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and <180 ng/cm2 of amino acids and hydrazine on the sampler head through precision cleaning, control of materials, and vigilance. Contamination is further characterized via witness material exposed to the spacecraft assembly and testing environment as well as in space. This characterization provided knowledge of the expected background and will be used in conjunction with archived spacecraft components for comparison with the samples when they are delivered to Earth for analysis. Most of all, the cleanliness of the OSIRIS-REx spacecraft was achieved through communication among scientists, engineers, managers, and technicians.

Hydrophobic labelling of membrane-embedded proteins with lipophilic reagents. Incorporation of [125I]INA and [125I]TID into B lymphocyte membrane immunoglobulins.

Hydrophobic labelling is frequently used in the study of membrane-inserted domains of intrinsic proteins. However, the published procedures, fail to incorporate sufficient radioactivity into membrane immunoglobulins of B lymphocytes to permit investigation of their subunit structures and associations with other proteins. In order to increase the specific radioactivity of [125I]iodonaphthylazide ([125I]INA), an improved method for the synthesis of the reagent was developed. In addition, the optimal conditions for labelling B lymphocytes with [125I]INA and the commercially available reagent 3-(trifluoromethyl)-3-(3'-[125I]iodophenyl)diazirine ([125I]TID) were elaborated. Under these optimized conditions, Ig molecules labelled with [125I]INA and [125I]TID were isolated and analysed in detail by SDS-PAGE. The usefulness of the two reagents for the investigation of lipid-embedded domains of membrane proteins is discussed.

Catatonic syndrome in a general psychiatric inpatient population: frequency, clinical presentation, and response to lorazepam.

In a prospective open trial conducted on a general psychiatric ward, the authors diagnosed catatonic syndrome 15 times in 12 patients over a 1-year period. These 12 patients represented 9% of all admissions. The following signs were present in two thirds or more of the episodes studied: immobility (100%), staring (92%), mutism (85%), withdrawal/refusal to eat (78%), posturing/grimacing (73%), and rigidity (66%). Other signs of catatonia were seen less frequently. Lorazepam 1 to 2 mg was administered in every case, and patients were evaluated at hourly intervals. Of the 15 episodes, 12 responded completely and dramatically to lorazepam treatment within 2 hours, 1 responded partially, and 2 had no response. Adverse effects were infrequent. A CNS abnormality or dysfunction was evident in 8 of the 12 responders, suggesting that a beneficial response to lorazepam is not limited to patients with pure psychogenic catatonia. The prompt recognition and treatment of catatonia may reduce morbidity in and length of stay for hospitalized psychiatric patients.

A sensitive bioassay for teicoplanin in serum in the presence or absence of other antibiotics.

A teicoplanin bioassay has been developed that is accurate, sensitive, and reliable. A linear relationship is obtained between the diameter of the zone of inhibition and log10 teicoplanin concentration in human serum over the range of 0.15 or 1.25 to 96 micrograms/ml using wells or paper filter disks, respectively. The assay medium devised consists of 50 g BBL Mueller-Hinton II Agar, 30 g NaCl, 8 g CaCl2, and 1.0 g citric acid (monohydrate) per liter of deionized water (resulting pH 5.1 +/- 0.1) and the assay organism Bacillus subtilis ATCC 6633. This system allows the assay of teicoplanin in the presence of commonly used aminoglycosides and in the presence of beta-lactams after inactivation by beta-lactamase. Additionally, it has the potential to be used in the presence of rifampin by using a rifampin-resistant strain of B. subtilis.

Bioassay of teicoplanin in serum containing rifampin or a beta-lactam antibiotic.

The purpose of this study was to develop bioassays for the measurement of teicoplanin in serum containing rifampin or a beta-lactam antibiotic. Use of rifampin-resistant Bacillus subtilis as indicator organism or pretreatment of the serum sample with Bacillus cereus penicillinase Type I (nafcillin, ticarcillin, mezlocillin) or Type II (cefazolin, cefuroxime, ceftazidime, ceftriaxone) effectively eliminated assay interference. Validation bioassays performed on two separate days utilizing triplicate coded serum samples containing 0 to 200 micrograms teicoplanin in combination with 40 micrograms/ml rifampin or 200 to 500 micrograms/ml beta-lactam showed no significant differences (p greater than 0.05, two-way analysis of variance) in analyte recovery between assay days. Regression analysis of each teicoplanin/rifampin or teicoplanin/beta-lactam data set yielded slope values of 0.92 to 1.01, intercept values of -0.45 to 0.84 and correlation coefficients of 0.9925 to 0.9990. Thus, serum teicoplanin can be quantitated accurately, precisely, and reproducibly in patients receiving concomitant rifampin or beta-lactam chemotherapy.

Tektite-bearing, deep-water clastic unit at the Cretaceous-Tertiary boundary in northeastern Mexico.

The hypothesis of Cretaceous-Tertiary (K-T) boundary impact on Yucatán, Mexico, predicts that nearby sites should show evidence of proximal impact ejecta and disturbance by giant waves. An outcrop along the Arroyo el Mimbral in northeastern Mexico contains a layered clastic unit up to 3 m thick that interrupts a biostratigraphically complete pelagic-marl sequence deposited at more than 400 m water depth. The marls were found to be unsuitable for determining magnetostratigraphy, but foraminiferal biostratigraphy places the clastic unit precisely at the K-T boundary. We interpret this clastic unit as the deposit of a megawave or tsunami produced by an extraterrestrial impact. The clastic unit comprises three main subunits. (1) The basal "spherule bed" contains glass in the form of tektites and microtektites, glass spherules replaced by chlorite-smectite and calcite, and quartz grains showing probable shock features. This bed is interpreted as a channelized deposit of proximal ejecta. (2) A set of lenticular, massive, graded "laminated beds" contains intraclasts and abundant plant debris, and may be the result of megawave backwash that carried coarse debris from shallow parts of the continental margin into deeper water. (3) At the top, several thin "ripple beds" composed of fine sand are separated by clay drapes; they are interpreted as deposits of oscillating currents, perhaps a seiche. An iridium anomaly (921 +/- 23 pg/g) is observed at the top of the ripple beds. Our observations at the Mimbral locality support the hypothesis of a K-T impact on nearby Yucatán.

Proximal impact deposits at the Cretaceous-Tertiary boundary in the Gulf of Mexico: a restudy of DSDP Leg 77 Sites 536 and 540.

Restudy of Deep Sea Drilling Project Sites 536 and 540 in the southeast Gulf of Mexico gives evidence for a giant wave at Cretaceous-Tertiary boundary time. Five units are recognized: (1) Cenomanian limestone underlies a hiatus in which the five highest Cretaceous stages are missing, possibly because of catastrophic K-T erosion. (2) Pebbly mudstone, 45 m thick, represents a submarine landslide possibly of K-T age. (3) Current-bedded sandstone, more than 2.5 m thick, contains anomalous iridium, tektite glass, and shocked quartz; it is interpreted as ejecta from a nearby impact crater, reworked on the deep-sea floor by the resulting tsunami. (4) A 50-cm interval of calcareous mudstone containing small Cretaceous planktic foraminifera and the Ir peak is interpreted as the silt-size fraction of the Cretaceous material suspended by the impact-generated wave. (5) Calcareous mudstone with basal Tertiary forams and the uppermost tail of the Ir anomaly overlies the disturbed interval, dating the impact and wave event as K-T boundary age. Like Beloc in Haiti and Mimbral in Mexico, Sites 536 and 540 are consistent with a large K-T age impact at the nearby Chicxulub crater.

Combined cytomorphologic and immunophenotypic analysis in the diagnostic workup of lymphomatous effusions.

OBJECTIVE: To analyze the results of cytomorphology and immunophenotyping in 54 patients with lymphomatous effusions. STUDY DESIGN: We report the results of cytomorphology and immunophenotyping in 54 patients with lymphomatous effusions. Twenty-three of the 54 had a previous diagnosis of NHL. In the remaining 31 patients, lymphomatous involvement was clinically suspected. RESULTS: Thirty-three lymphomatous effusions were positive for involvement by NHL. Twenty-one of these 33 patients (64%) had a previous diagnosis of NHL. Of the remaining 12 patients with newly diagnosed NHL, 11 had high grade lymphoma, and one had follicular center lymphoma. Twenty effusions were considered to be reactive; only two of these patients had NHL. One effusion revealed involvement by a previously unknown carcinoma. We observed seven false negative results if only one of both methods was considered. A high grade NHL was not diagnosed by immunophenotyping in one case, and six cases of low grade NHL could not be detected by cytomorphology. The combined strategy of cytomorphology and immunophenotyping had a sensitivity of 100% and specificity of 100% in our study, confirmed by follow-up studies. CONCLUSION: Both methods have shown difficulties in the examination of lymphomatous effusions. Cytomorphology has problems distinguishing reactive effusions from low grade NHL. The detection of high grade NHL by immunophenotyping is difficult. However, both methods together offer the advantage of dual staining ability and are most helpful in distinguishing clonal lymphomatous from reactive effusions.

Fine needle aspiration cytology in extramedullary plasmacytoma.

OBJECTIVE: Extramedullary plasmacytoma is a rare plasma cell neoplasm. It can occur as the sole manifestation of plasma cell neoplasm, as a metastasis from another extramedullary plasmacytoma, as a solitary plasmacytoma of the bone or as a consequence of multiple myeloma. These plasma cell tumors can occur anywhere and have to be differentiated from other neoplasms, infectious processes and chloroma. STUDY DESIGN: We report the findings of fine needle aspiration cytology (FNAC) in 18 patients with extramedullary plasmacytoma. In six patients extramedullary plasmacytoma was the initial presentation of plasma cell neoplasm. In the remaining 12 patients the tumors occurred under or after treatment of plasma cell disease. RESULTS: Eleven lesions were located in the skin, seven in the lymph nodes, one in the liver and another in the spleen. Two patients with known diagnoses of plasma cell disease were thought, before FNAC, to have an infection, and two had a histologic diagnosis of non-Hodgkin's lymphoma. In 13 of 18 patients, cytologic smears showed anaplastic plasma cells. CONCLUSION: FNAC is a front-line investigative procedure in diagnosing extramedullary plasmacytoma.

Healing characteristics of small-calibre vascular prostheses coated with plasmin-treated fibrin--an experimental study.

BACKGROUND: The autogenous vein represents the graft material of choice in crural and pedal bypass surgery. Because of the numerous problems concerning the graft harvesting and the quality of autogenous vein material an equally good allogenous graft is urgently needed. Up to the present times no such graft material has been able to achieve the success of vein grafts. METHODS: We investigated the knitted polyester prosthesis Terumo PF-V (Terumo Comp., Japan), diameter 5 mm with outer reinforce, which is characterized by a new coating of plasmin-treated fibrin. Grafts were implanted as bypass into the ligated carotid (n = 10) and femoral arteries (n = 10) of 10 dogs (beagles). As a control 5 mm-ePTFE-prostheses (Impra Carboflo) were implanted simultaneously on the contralateral side. RESULTS: After 6 months, seven of 20 PF-V-grafts and 8 of 20 PTFE-grafts were patent. All prostheses presented with good macroscopic healing characteristics. In the patent grafts, angiography showed no substantial stenoses. The histological examination of the material was performed using light microscopy, transmission polarising microscopy, scanning electron microscopy, and transmission electron microscopy. Both types of prostheses showed the typical pattern of graft healing by migration of mesenchymal cells through the prosthesis, formation of capillaries, and growing of a neointima with endothelium-like cells. All failed bypass grafts presented with an occluding proliferation from the arterial wall into the anastomotic region. CONCLUSIONS: Using clinically or histologically evaluation, neither graft demonstrated superiority over the other. The results indicate that the coating plays only a minor role for graft healing if any. For proper graft function, the arterial wall proliferation at the anastomotic region, which is not dependent on the type of prosthesis, appears to be most important. The overall results concerning both types of prostheses were disappointing.

Virtual reality in the operating room of the future.

In cooperation with the Max-Delbrück-Centrum/Robert-Rössle-Klinik (MDC/RRK) in Berlin, the Fraunhofer Institute for Computer Graphics is currently designing and developing a scenario for the operating room of the future. The goal of this project is to integrate new analysis, visualization and interaction tools in order to optimize and refine tumor diagnostics and therapy in combination with laser technology and remote stereoscopic video transfer. Hence, a human 3-D reference model is reconstructed using CT, MR, and anatomical cryosection images from the National Library of Medicine's Visible Human Project. Applying segmentation algorithms and surface-polygonization methods a 3-D representation is obtained. In addition, a "fly-through" the virtual patient is realized using 3-D input devices (data glove, tracking system, 6-DOF mouse). In this way, the surgeon can experience really new perspectives of the human anatomy. Moreover, using a virtual cutting plane any cut of the CT volume can be interactively placed and visualized in realtime. In conclusion, this project delivers visions for the application of effective visualization and VR systems. Commonly known as Virtual Prototyping and applied by the automotive industry long ago, this project shows, that the use of VR techniques can also prototype an operating room. After evaluating design and functionality of the virtual operating room, MDC plans to build real ORs in the near future. The use of VR techniques provides a more natural interface for the surgeon in the OR (e.g., controlling interactions by voice input). Besides preoperative planning future work will focus on supporting the surgeon in performing surgical interventions. An optimal synthesis of real and synthetic data, and the inclusion of visual, aural, and tactile senses in virtual environments can meet these requirements. This Augmented Reality could represent the environment for the surgeons of tomorrow.

Masked intentions: the masquerade of killing thoughts used to justify dehydrating and starving people in a "persistent vegetative state" and people with other profound neurological impairments.

Denying food and water to profoundly impaired people who may not be conscious, or may only be "minimally" conscious, raises challenging ethical issues. While there is growing support for withdrawing/withholding food and water (assisted nutrition and hydration, or "AHN") from people described as being in a "persistent vegetative state" ("PVS") and people with other profound neurological impairments, such as advanced dementia, the issue remains controversial, and for many, unresolved. In this article, the author argues that if a profoundly impaired person is not imminently dying from a disease process, denying food and water causes him or her to die of dehydration and starvation. When provision of food and water does not create excessive burdens (such as extreme pain and discomfort), and if the food and water can be digested and absorbed, denying such nourishment is immoral and unethical. Under these circumstances, this denial (by commission or omission) is motivated by a real intention to cause death, whether or not that intention is explicitly recognized.