The record of Martian climatic history in cores and its preservation

Among the questions to be addressed by a Mars Sample Return Mission are the history of the Martian climate and the mechanisms that control the volatile cycles. Unfortunately, the evidence that bears most strongly on those issues lies in the volatile distribution in, and physical configuration of, a very delicate and volatile system: the uppermost Martian regolith. Some useful measurements to be made on returned samples of the regolith are identified, along with the many critical considerations in ensuring the usefulness of returned samples

The use of aminoglycoside antibiotic therapy in neutropaenic patients with haematological disease

The use of aminoglycosides in the treatment of the febrile neutropaenic patient with haematological disease is difficult and often suboptimal. This study reviews the available literature to establish therapeutic guidelines in this population and then reports the use of a Bayesian statistics based predictive model to implement and manage therapy in 10 patients. A review of the literature on aminoglycoside Pharmacology and clinical use is essential to determine therapeutic guidelines for this population. Aminoglycosides are amino sugars in glycosidic linkage and are polycations at physiological PH. The antibiotic effect is mediated through inhibition of protein synthesis and disruption of cell membrane integrity. Principal use is in treatment of Gram negative infection although aminoglycosides have activity against some Gram positive organisms including staphylococci. Aminoglycosides are inactive against anaerobes. Acquired resistance is mediated by bacterial enzymatic drug metabolism. Aminoglycosides are nephro- and ototoxic, this is the major constraint in clinical use

SO2 on Io: A thermodynamic perspective

The presence of condensed SO2 on Io mandates a finite abundance of SO2 vapor which must be present, regardless of plume activity. The absorption of SO2 was measured on particulate sulfur and the equilibrium between absorbed SO2, SO2 vapor, and SO2 ice examined, based upon measurements and simple thermodynamic considerations

Drug allergy

Drug allergy is an important complication in theuse of agents such as penicillins, cephalosporins, sulphonamides, insulin and streptokinase. The allergenic properties of drugs are a function of molecular size and chemical reactivity. Factors determining an individual's risk of an allergic response are not fully understood but include genetic predisposition, prior exposure, route of administration, drug dosage, age and concomitant disease. The most dangerous but least common form of drug allergy is generalised anaphylaxis. The majority of reactions are non-anaphylactic and involve the skin, with a lesser incidence of haematological, renal, :musculoskeletal, cardiorespiratory and other systemic manifestations. The only definitive test for allergy in a patient with a history of previous allergic reaction is rechallenge, a dangerous and seldom indicated procedure. An alternative is skin testing, but this requires an experienced practitioner and has intrinsic risk. In vitro testing may be of value in predicting the risk of re-challenge. Safe use of a suspect drug requires a careful assessment of risk and a cautious approach. Use of an offending drug in a high-risk patient is rarely indicated, but if it is considered essential, initial therapy or desensitisation in an intensive care environment is recommended

The Role of Integrin-associated Protein “PINCH” in Kidney Development

PINCH (a particularly interesting new cysteine-histidine-rich protein) is a protein that binds with Integrin-linked kinase and Parvin, to form an IPP complex. This complex is formed only when integrin molecules are activated upon interaction with the basement membrane. The IPP complex then acts as a platform for other proteins to come together and regulate cell signaling to and from the extracellular matrix (ECM). This allows for various cellular activities to progress like cell adhesion, migration, proliferation, etc. There are two types of PINCH proteins, PINCH-1 and PINCH-2. Studies from our group have shown that the lack of PINCH-1 in the kidney results in a branching phenotype and smaller kidneys in mice. The cells showed diminished potential to adhere, migrate and proliferate. There is no significant difference in phenotype when PINCH-2 is deleted. In the present study, we use conditional double knockout mice and cells in culture to look at the additive effects of the two PINCH proteins. Stained kidney cross sections will be analyzed and the PINCH null cells will be used in cell adhesion and migration studies. We have preliminary data to show that the deletion of both PINCH-1 and PINCH-2 genes results in a severe developmental phenotype in mouse kidney and corroborates in vitro studies

Conceptual designs for in situ analysis of Mars soil

A goal of this research is to develop conceptual designs for instrumentation to perform in situ measurements of the Martian soil in order to determine the existence and nature of any reactive chemicals. Our approach involves assessment and critical review of the Viking biology results which indicated the presence of a soil oxidant, an investigation of the possible application of standard soil science techniques to the analysis of Martian soil, and a preliminary consideration of non-standard methods that may be necessary for use in the highly oxidizing Martian soil. Based on our preliminary analysis, we have developed strawman concepts for standard soil analysis on Mars, including pH, suitable for use on a Mars rover mission. In addition, we have devised a method for the determination of the possible strong oxidants on Mars

The Phoenix TECP Relative Humidity Sensor: Revised Results

The original calibration function of the RH sensor on the Phoenix mission's Thermal and Electrical Conductivity Sensor (TECP), has been revised to correct the erroneously-published original calibration equation, to demonstrate the value of this unique data set, and to improve characterization of H2O exchange between the martian regolith and atmosphere. TECP returned two data streams, the temperature of the electronics analog board (Tb) and the digital 12-bit output of the RH sensor (DN), both of which are required to uniquely specify the H2O abundance. Because the original flight instrument calibration was performed against a pair of hygrometers that measured frost point (Tf), the revised calibration equation is also cast in terms of frost point. The choice of functional form for the calibration function is minimally constrained. A series of profiles across the calibration data cloud at constant DN and Tb does not reveal any evidence of a complex functional form. Therefore, a series of polynomials in both DN and Tb was investigated, along with several non-linear functions of DN and Tb

Absorption of the Martian regolith: Specific surface area and missing CO(sub 2)

For most estimates of available regolith and initial degassed CO(sub 2) inventories, it appears that any initial inventory must have been lost to space or incorporated into carbonates. Most estimates of the total available degassed CO(sub 2) inventory are only marginally sufficient to allow for a major early greenhouse effect. It is suggested that the requirements for greenhouse warming to produce old dessicated terrain would be greatly lessened if groundwater brines rather than rainfall were involved and if a higher internal gradient were involved to raise the water (brine) table, leading to more frequent sapping