Induction of the zebrafish ventral brain and floorplate requires cyclops/nodal signalling

Zebrafish cyclops (cyc) mutations cause deficiencies in the dorsal mesendoderm and ventral neural tube, leading to neural defects and cyclopia. Here we report that cyc encodes a transforming growth factor-beta (TGF-beta)-related intercellular signalling molecule that is similar to mouse nodal. cyc is expressed in dorsal mesendoderm at gastrulation and in the prechordal plate until early somitogenesis. Expression reappears transiently in the left lateral-plate mesoderm, and in an unprecedented asymmetric pattern in the left forebrain. Injection of cyc RNA non-autonomously restores sonic hedgehog-expressing cells of the ventral brain and floorplate that are absent in cyc mutants, whereas inducing activities are abolished by cyc, a mutation of a conserved cysteine in the mature ligand. Our results indicate that cyc provides an essential non-cell-autonomous signal at gastrulation, leading to induction of the floorplate and ventral brain.     

Mechanical properties and thermal expansion behaviour in leucite containing materials

The effect of a change in sodium content and thermal history on a leucite composition material produced by a coprecipitation process was studied. Five materials with formulae of (K(_1–x ),Na _x )₂O-Al₂O₃-4SiO₂ (x= 0.0, 0.2, 0.4, 0.6, 0.8) were investigated for differences in phases, thermal expansion, and strength. Strengths of up to 175 MPa were obtained for a leucite composition material (x = 0.0). Sodium was effective in lowering the thermal expansion coefficients of these materials. Leucite was linked to higher flexural strengths, but was present only in those specimens which were sintered at 1200 °C. Leucite was not present in those specimens sintered at 1100 °C or lower. Porosity was present in all specimens sintered at 1000 °C or higher.     

Scaling laws for integrated optics waveguides

The accurate design of integrated optical S bends, power splitters, and directional couplers is described through a minimum number of normalized parameters. General design curves showing these normalized parameters for waveguides with a step refractive index profile and a quadratic core cross section are given. Thus a wide variety of integrated optical components may be designed accurately without the use of time-consuming numerical methods.     

The effect on the likelihood of further pregnancy of placental abruption and the rate of its recurrence

OBJECTIVE: To assess the effect of having a placental abruption on 1. the probability of having further pregnancies, and 2. the rate of recurrence in such pregnancies. DESIGN: A cohort study based on the Medical Birth Registry of Norway. RESULTS: From 1967 to 1989, placental abruption occurred in 218/4951 subsequent deliveries after a placental abruption index case. After placental abruption with perinatal survival in the first delivery 59% of women had a further delivery, compared with 71% who did not have placental abruption at delivery. After a perinatal loss corresponding rates were 83% and 85%, respectively. Odds ratios of recurrence of abruption, crude and adjusted for maternal age, birth order and time period were 7.1 and 6.4, respectively. No secular trends were found. Caesarean section rates increased and were higher in pregnancies with recurrent placental abruption and in subsequent pregnancies without placental abruption than in the total birth population. CONCLUSIONS: Women who have placental abruption are less likely than other women to have another pregnancy. For women who do have subsequent pregnancies placental abruption occurs significantly more frequently.     

Towards functional labeling of utility vehicle point clouds for humanoid driving

We present work on analyzing 3-D point clouds of a small utility vehicle for purposes of humanoid robot driving. The scope of this work is limited to a subset of ingress-related tasks including stepping up into the vehicle and grasping the steering wheel. First, we describe how partial point clouds are acquired from different perspectives using sensors, including a stereo camera and a tilting laser range finder. For finer detail and a larger model than one sensor view alone can capture, a Kinect Fusion (Izadi et al. in KinectFusion: realtime 3D reconstruction and interaction using a moving depth camera, 2011)-like algorithm is used to integrate the stereo point clouds as the sensor head is moved around the vehicle. Second, we discuss how individual sensor views can be registered to the overall vehicle model to provide context, and present methods to estimate both statically and dynamically several geometric parameters critical to motion planning: (1) the floor height and boundaries defined by the seat and the dashboard, and (2) the steering wheel pose and dimensions. Results are compared using the different sensors, and the usefulness of the estimated quantities for motion planning is also addressed.     

Selecting users for participation in IT projects: Trading a representative sample for advocates and champions?

The selection of users for participation in IT projects involves trade-offs between multiple criteria, one of which is selecting a representative cross-section of users. This criterion is basic because trading it for other criteria means basing designs on information biased toward some user groups at the expense of others. Based on interviews in development and customer organizations we find that their criteria for user selection favor persons who can contribute to the progress of the IT project over persons who are representative of the full range of users. A highly valued contribution from participating users is the ability to advocate a vision for the system and champion its organizational implementation. A survey in one customer organization shows that respondents’ personal traits explain up to 31% of the variation in their experience of aspects of the usability of a recently introduced system. Thus, unless participating users are representative as to these personal traits, IT projects may, inadvertently, bring about systems that will fail to satisfy many users.     

Short-term effects of captopril on exercise tolerance in patients with chronic stable angina pectoris and normal left ventricular function

A double-blind, placebo-controlled, crossover study was carried out to evaluate the short-term effects of captopril on exercise tolerance in 18 normotensive patients with chronic stable angina pectoris and normal left ventricular function. Captopril 25 mg (or placebo) was given twice, i.e. in the evening (10 p.m.) and the following morning (8 a.m.), prior to a maximal symptom-limited bicycle exercise test (11 a.m.). Captopril reduced the systolic and diastolic blood pressures at rest (p < 0.01) without causing any reflex tachycardia. The time to onset of S-T depression was prolonged (p < 0.05), and the maximal S-T depression was reduced (p < 0.02). No differences were found between captopril and placebo in total exercise duration or time to onset of angina. The effects of captopril on exercise-induced ischemia were demonstrated most clearly in patients who responded with a greater than 10 mm Hg fall in the resting systolic blood pressure. In conclusion, this study suggests that captopril has anti-ischemic properties, which may be of importance in the treatment of patients with chronic stable angina and normal left ventricular function. These beneficial effects probably relate to a reduction in afterload and myocardial wall stress and therefore a reduction in myocardial oxygen demand.     

Prognostic value of cellular proliferation and histologic grade in follicular lymphoma

The clinical usefulness of histologic grading in follicular lymphoma (FL) is controversial and is further compromised by the subjective nature and poor reproducibility of most systems in current use. Therefore, we decided to objectively evaluate the importance of cellular proliferation in FL, along with the current grading systems. We studied 106 patients with FL who were uniformly staged and aggressively treated. A proliferative index (PI) was determined quantitatively using an automated image analyzer and a new Ki-67 antibody that stains archival paraffin tissues. The cases were also subclassified according to the Berard, Rappaport, Luke-Collins, and Jaffe methods, and survival analysis was performed. Patients with a low PI (< 40%) had a significantly longer overall survival (OS) than those with a high PI (> or = 40%), but the PI did not predict failure-free survival (FFS). The mean PI correlated well with the subgroups in each of the various classifications. All four of the classification methods were predictive of OS, but only the Berard method appeared to predict FFS and suggest that a proportion of patients with FL may be curable. In multivariate analysis, histologic classification was the only independent predictor of OS (Berard method: relative risk, 3.1) and the International Prognostic Index was the only independent predictor of FFS (relative risk, 2.3). We conclude that the Berard method for grading of FL is clinically useful and, along with the International Prognostic Index, should be included in future clinical studies of FL. The measurement of cellular proliferation does not appear to add additional useful information in FL.     

The cloning and chromosomal mapping of two novel human opioid-somatostatin-like receptor genes, GPR7 and GPR8, expressed in discrete areas of the brain

Following the cloning of the opioid receptors mu, kappa, and delta, we conducted a search for related receptors. Using oligonucleotides based on the opioid and also the structurally related somatostatin receptors, we amplified genomic DNA using the polymerase chain reaction and isolated fragments of novel G protein-coupled receptor genes. Two of these gene fragments designated clones 12 and 11 were used to isolate the full-length genes. The intronless coding sequences of these genes, named GPR7 and GPR8, shared 70% identity with each other, and each shared significant similarity with the sequences encoding transmembrane regions of the opioid and somatostatin receptors. GPR7 was mapped to chromosome 10q11.2-q21.1 and GPR8 to chromosome 20q13.3. Northern blot analysis using human mRNA demonstrated expression of GPR7 mainly in cerebellum and frontal cortex, while GPR8 was located mainly in the frontal cortex. In situ hybridization revealed expression of GPR7 in the human pituitary. A partial sequence of the mouse orthologue of GPR7 was obtained, and in situ hybridization demonstrated expression in discrete nuclei of brain, namely suprachiasmatic, arcuate, and ventromedial nuclei of hypothalamus. A stable cell line expressing the GPR7 gene was created, but expression levels of the receptor were low. The available pharmacology indicated binding to several opioid drugs such as bremazocine, levorphanol, and beta-FNA, but not to the opioid receptor subtype-selective mu, delta, or kappa agonists.     

A 37.5 kb region of yeast chromosome X includes the SME1, MEF2, GSH1 and CSD3 genes, a TCP-1-related gene, an open reading frame similar to the DAL80 gene, and a tRNA(Arg)

The complete DNA sequence of cosmid clone p59 comprising 37,549 bp derived from chromosome X was determined from an ordered set of subclones. The sequence contains 14 open reading frames (ORFs) containing at least 100 consecutive sense codons. Four of the ORFs represent already known and sequenced yeast genes: B645 is identical to the SME1 gene encoding a protein kinase, required for induction of meiosis in yeast, D819 represents the MEF2 gene probably encoding a second mitochondrial elongation factor-like protein, D678 is identical to the yeast GSH1 gene encoding gamma-glutamylcysteine synthetase and B746 is identical to the CSD3 gene, which plays an as yet unidentified role in chitin biosynthesis and/or its regulation. The deduced amino acid sequence of A550 is 63% identical to the Cc eta subunit of a murine TCP-1-containing chaperonin and more than 35% identical to thermophilic factor 55 from Sulfolobus shibatae, as well as to a number of proteins belonging to the chaperonin TCP-1 family. Open reading frame F551 exhibits homology to two regions of the DAL80 gene located on yeast chromosome XI encoding a pleiotropic negative regulatory protein. In addition, extensive homology was detected in three regions including parts of ORFs A560, B746/CSD3 and the incomplete ORF C852 to three consecutive ORFs of unknown function in the middle of the right arm of chromosome XI. Finally, the sequence contained a tRNA(Arg3) (AGC) gene.