The radial gradient of interplanetary radiation measured by Mariners 4 and 5

Interplanetary radiation radial gradient measured from Mariners 4 and

Double heterostructure lasers with facets formed by a hybrid wet and reactive-ion-etching technique

Double heterostructure lasers were fabricated in which one of the laser facets was produced by a hybrid wet and reactive-ion-etching technique. This technique is suitable for GaAs/GaAlAs heterostructure lasers and utilizes the selectivity of the plasma in preferentially etching GaAs over GaAlAs. Lasers fabricated by this technique are compatible with optoelectronic integration and have threshold currents and quantum efficiency comparable to lasers with both mirrors formed by cleaving. The technique enables the use of relatively higher pressures of noncorrosive gases in the etch plasma resulting in smoother mirror surfaces and further eliminates the nonreproducibility inherent in the etching of GaAlAs layers

A Case-control study in Clinical Spectrum and Risk factors for Myocardial Infarction in the young (≤ 40 yrs)

Chest Pain is the cardinal symptom in young myocardial infarction. Breathlessness, sweating, radiation, vomiting, palpitation, sweating are common features symptoms. Signs of hypertension, S3, S4, crackles, were commonly seen. On few occasions infarction also occurred in the absence of physical signs or symptoms. Key factors influencing the development of myocardial infarction were non modifiable risk factors such as age, sex, family history. Smoking is probably the single most important risk factor. There is a strong relationship between cigarette smoking and coronary artery heart disease in young individuals. The risk is also closely related to plasma LDL cholesterol, and inversely related to HDL cholesterol concentration. Obesity particularly central or truncal is an independent risk factor. Additional risk factors such as diabetes, physical inactivity added to the adverse impact. The effect of risk factors is multiplicative rather than Additive. Thus people with the combination of risk factors (smoking, hypertension, diabetes) have the greatest risk of developing myocardial infarction. Prevention can aim at modifying the risk factors like cessation of smoking, reduction of weight, reduction of salt intake, dietary changes, increase physical activity and control of psychosocial stress. This will have a tremendous impact in reducing the incidence of myocardial infarction in the young

Approximate Hypergraph Coloring under Low-discrepancy and Related Promises

A hypergraph is said to be $\chi$-colorable if its vertices can be colored with $\chi$ colors so that no hyperedge is monochromatic. $2$-colorability is a fundamental property (called Property B) of hypergraphs and is extensively studied in combinatorics. Algorithmically, however, given a $2$-colorable $k$-uniform hypergraph, it is NP-hard to find a $2$-coloring miscoloring fewer than a fraction $2^{-k+1}$ of hyperedges (which is achieved by a random $2$-coloring), and the best algorithms to color the hypergraph properly require $\approx n^{1-1/k}$ colors, approaching the trivial bound of $n$ as $k$ increases. In this work, we study the complexity of approximate hypergraph coloring, for both the maximization (finding a $2$-coloring with fewest miscolored edges) and minimization (finding a proper coloring using fewest number of colors) versions, when the input hypergraph is promised to have the following stronger properties than $2$-colorability: (A) Low-discrepancy: If the hypergraph has discrepancy $\ell \ll \sqrt{k}$, we give an algorithm to color the it with $\approx n^{O(\ell^2/k)}$ colors. However, for the maximization version, we prove NP-hardness of finding a $2$-coloring miscoloring a smaller than $2^{-O(k)}$ (resp. $k^{-O(k)}$) fraction of the hyperedges when $\ell = O(\log k)$ (resp. $\ell=2$). Assuming the UGC, we improve the latter hardness factor to $2^{-O(k)}$ for almost discrepancy-$1$ hypergraphs. (B) Rainbow colorability: If the hypergraph has a $(k-\ell)$-coloring such that each hyperedge is polychromatic with all these colors, we give a $2$-coloring algorithm that miscolors at most $k^{-\Omega(k)}$ of the hyperedges when $\ell \ll \sqrt{k}$, and complement this with a matching UG hardness result showing that when $\ell =\sqrt{k}$, it is hard to even beat the $2^{-k+1}$ bound achieved by a random coloring.Comment: Approx 201

Voyager 1 and 2 measurements of radial and latitudinal cosmic ray gradients during 1981 - 1984

The cosmic ray radial gradient was determined during 1981-84 using data from very similar detectors onboard spacecraft Voyagers 1 and 2 (radial separation approx. 6 AU, heliolatitude separation approx. 25 deg.) and from the Earth-orbiting satellite IMP 8. The principal result is that the radial gradient over this period decreased at the rate approx. 2.0%/AU between 1 and 16 AU and approx. 0.6%/AU between approx. 16 and 22 AU

The marketing orientation of small and medium enterprises: An Australian study

The market orientation construct has emerged as a key marketing theme in the 1990\u27s. While the concept of being focussed on the market (customers and competitors) has been known since the early 1950\u27s (e.g. Drucker,1954), putting the concept into practice through a set of specific actions has eluded many organisations and academics. As a result, market orientation (also termed market focus, customer focus and competitor focus) had remained a business philosophy (Bennett & Cooper, 1979: Felton, 1959; Konopa & Calabro,1971) more than a strategic approach. While there have been sporadic attempts at defining or operationalisinga marketing or customer orientation in the past (Gronrnos, 1989: Kotler, 1977: Masiello, 1988: Webster,1988), the first serious effort in the early 1990\u27s when Kohli and Jaworski (1990) and Narver and Slater (1990 defined market orientation as a set of organisational activities or behaviours. Narver and Slater also found a positive link between having such an orientation and business performance. The emphasis in both models was on obtaining and understanding customers and competitors and responding to customers\u27 needs better than competitors through a coordinated effort across the organisation. Subsequently a number of studies have supported the positive relationship between market orientation and business performance. However, results have not been consistent and several variables have been shown to moderate the market orientation performance relationship. All of the major market orientation studies have been undertaken within large organisations and very little is known about the market orientation of small and medium enterprises (SMEs), or of its relationship to their performance. It is recognised that SMEs are different from large businesses some of their marketing practices are unique to SME. Given this uniqueness, the present research examined the applicability of existing market orientation constructs and models to SMEs. For this purpose, Kohli and Jaworski\u27s and Narver and Slater\u27s constructs were modified and some unique SME items were added. Following a staged research approach, as recommended by Churchill (1979), a randomly chosen sample of Australian SMEs was surveyed. In all, more than 700 responses were received, of which 542, were used in the present study. The results obtained suggested that while a form of market orientation existed in SMEs, its operationalisation was different. Of Kohli and Jaworski’s (1990) three dimensions, (intelligence generation, dissemination and organisational response), organisational response could not be supported. The study also provided support for Narver and Slater\u27s (1990) customer and competitor orientation constructs. The third construct \u27inter-functional coordination\u27 was not included as early qualitative interviews made it clear that it had no meaning in an SME context. Customer and competitor orientations emerged as distinct constructs but the interrelationship between the two suggested the presence of a higher order \u27market orientation\u27 construct. Compared to the organisations analysed in earlier studies, the SMEs in the current study were small in size and very few had multiple functional areas. In most of the businesses, marketing did not exist as a separate function. Consequently there was 110 support for constructs such as organisational response and inter-functional coordination. The informal nature of SMEs marketing activities was evident in the market orientation constructs. It appeared that SMEs collect their intelligence through informal means. Their marketing activities were also based more on intuition than logic. Apart from customer and competitor orientations, a customer service orientation emerged as an important element. Having a customer service orientation led to customer satisfaction and, hence, to repeal business, which was considered to be extremely important by the small businesses surveyed. Having a customer service orientation also had a positive impact on the organisational commitment of employees, repeat business and business performance. The overall impact of customer orientation and competitor orientation on business performance was positive, but small. This was not surprising as respondents took a casual or intuitive approach to marketing. It seems that small business performance is constrained by factors other than marketing, such as the availability of resources. Further, even among large businesses. The market orientation-performance relationship has not been consistently positive or significant. The present results suggest that market orientation, as practised in large businesses, or as articulated by academics, may not be applicable to SMEs and that customer service elements needed to be included in the model. As regards performance, the results obtained suggest that factors other than marketing are also critical and fun her research is needed to tease out the nature of these additional factors

Magnetoresistance in the superconducting state at the (111) LaAlO3_3/SrTiO3_3 interface

Condensed matter systems that simultaneously exhibit superconductivity and ferromagnetism are rare due the antagonistic relationship between conventional spin-singlet superconductivity and ferromagnetic order. In materials in which superconductivity and magnetic order is known to coexist (such as some heavy-fermion materials), the superconductivity is thought to be of an unconventional nature. Recently, the conducting gas that lives at the interface between the perovskite band insulators LaAlO$_3$ (LAO) and SrTiO$_3$ (STO) has also been shown to host both superconductivity and magnetism. Most previous research has focused on LAO/STO samples in which the interface is in the (001) crystal plane. Relatively little work has focused on the (111) crystal orientation, which has hexagonal symmetry at the interface, and has been predicted to have potentially interesting topological properties, including unconventional superconducting pairing states. Here we report measurements of the magnetoresistance of (111) LAO/STO heterostructures at temperatures at which they are also superconducting. As with the (001) structures, the magnetoresistance is hysteretic, indicating the coexistence of magnetism and superconductivity, but in addition, we find that this magnetoresistance is anisotropic. Such an anisotropic response is completely unexpected in the superconducting state, and suggests that (111) LAO/STO heterostructures may support unconventional superconductivity.Comment: 6 Pages 4 figure

Recent Developments in Anti-Tank Ammunition

Every advance in anti-tank ammunition has been matched by advances in armour material or vice-versa. This applies both to kinetic energy and chemicai energy type of ammunition. Today the kinetic energy ammunition appears to have an upper hand over armour. In t his paper, a brief survey of the modern FSAPDS ammunition, its design aspects and its material technology is made.The capabilities of HEAT type of ammunition are also discussed and the likely trends in ammunition technology are indicated. Some futuristic developments in the field of propulsion are briefly mentioned