Valley Networks and the Record of Glaciation on Ancient Mars.

The lack of evidence for large-scale glacial landscapes on Mars has led to the belief that ancient glaciations had to be frozen to the ground. Here we propose that the fingerprints of Martian wet-based glaciation should be the remnants of the ice sheet drainage system instead of landforms generally associated with terrestrial ice sheets. We use the terrestrial glacial hydrology framework to interrogate how the Martian surface gravity affects glacial hydrology, ice sliding, and glacial erosion. Taking as reference the ancient southern circumpolar ice sheet that deposited the Dorsa Argentea formation, we compare the theoretical behavior of identical ice sheets on Mars and Earth and show that, whereas on Earth glacial drainage is predominantly inefficient, enhancing ice sliding and erosion, on Mars the lower gravity favors the formation of efficient subglacial drainage. The apparent lack of large-scale glacial fingerprints on Mars, such as drumlins or lineations, is to be expected.

Dynamic processes at the ends of collisional mountain chains.

Understanding of the relationships between tectonic deformation and exhumation in the Himalaya remains incomplete, especially at the ends of the chain.

Climate controls on erosion in tectonically active landscapes.

The ongoing debate about the nature of coupling between climate and tectonics in mountain ranges derives, in part, from an imperfect understanding of how topography, climate, erosion, and rock uplift are interrelated. Here, we demonstrate that erosion rate is nonlinearly related to fluvial relief with a proportionality set by mean annual rainfall. These relationships can be quantified for tectonically active landscapes, and calculations based on them enable estimation of erosion where observations are lacking. Tests of the predictive power of this relationship in the Himalaya, where erosion is well constrained, affirm the value of our approach. Our model allows estimation of erosion rates in fluvial landscapes using readily available datasets, and the underlying relationship between erosion and rainfall offers the promise of a deeper understanding of how climate and tectonic evolution affect erosion and topography in space and time and of the potential influence of climate on tectonics.

Spontaneous superior ophthalmic vein thrombosis: a rare entity with potentially devastating consequences.

PURPOSE: Spontaneous superior ophthalmic vein thrombosis (SOVT) is a rare entity. We describe three patients with spontaneous ophthalmic vein thrombosis, each with various risk factors. PATIENTS AND METHODS: A retrospective review of three patients with a diagnosis of superior ophthalmic vein thrombosis. Clinical characteristics, radiographic features, management techniques and outcomes are described. RESULTS: All patients presented with unilateral painful proptosis. Two patients had intact light perception, whereas one patient presented with absent light perception. All patients had identifiable risk factors for thrombosis, which included sickle cell trait, hereditary hemorrhagic telangectasia and colon cancer with recurrent deep vein thrombosis. Anticoagulation was initiated in two patients. Resolution of proptosis was seen in all patients, with no recovery of vision in one patient. CONCLUSIONS: Risk factors for spontaneous superior ophthalmic vein thrombosis are multifactorial. MRI and MRV confirm the diagnosis of SOVT. Despite urgent intervention devastating visual loss may occur.

A computer-aided system for planning acute care bed need in Michigan.

As part of an effort within Michigan to promote cost containment and equitably distribute hospital resources, the Acute Care Bed Need Methodology (ACBNM), a model for determining bed need based on normative use rates, was created. We describe herein the ACBNM, the associated interactive computer system, and the data base requirements, and make suggestions for improving the methodology. We also discuss the functions the ACBNM has served in Michigan and the role it could serve in future health planning efforts.

Voluntary control of two lateralized conscious states: validation by electrical and behavioral studies.

A subject is described who can voluntarily select and hold either of two qualitatively different states of consciousness. Evidence is presented which confirmed differential left or right hemisphere dominance in each state. Asymmetries of EEG alpha and task performance scores indicated a state-dependent shift in functional lateralization. Evoked response studies showed directional changes in rate of interhemispheric transmission correlated with state-related hemisphere dominance. These findings demonstrated that capability for voluntary endogenous control of cerebral dominance under natural conditions.

Psychological characteristics of males with secondary erectile failure.

This study was designed to obtain objective data on the personality profiles of two groups of males with a primary complaint of erectile failure and compare them to a group of psychiatric patients unselected for sexual dysfunction and to a sexually "normal" control group. Utilizing the Eysenck Personality Inventory, the Institute of Personality and Ability Testing Anxiety Scale, Symptom Checklist, and the Minnesota Multiphasic Personality Inventory, it was determined that males applying to a university/county hospital sex-dysfunction clinic appeared similar to patients seen in the same clinic who were unselected for sex dysfunction and more psychologically disturbed than patients with the same complaint applying for treatment at a private clinic. All three groups showed more psychopathology than sexually normal males. The implications of these findings are discussed.

Hemispheric dysfunction in schizophrenia: assessment by visual perception tasks.

Before and after a double-blind trial of haloperidol vs. mesoridazine, 24 hospitalized schizophrenics performed visual perception tasks designed to assess function of the cerebral hemispheres. Tasks involved identifying as "same" or "different" two images (either letters, digits, or unfamiliar shapes) projected tachistoscopically to the right or left visual field or to both together. Multivariate analysis of variance related response latency and accuracy to task type, hemisphere stimulated, and pre- vs. posttreatment testing. Both before and after treatment, subjects responded most slowly and least accurately to letter-matching. Bilateral presentation of stimuli resulted in faster and more accurate responses, except on shape-matching. Neuroleptic treatment improved speed and accuracy overall, though not under certain task conditions. Results accorded more with an impairment in verbal processing and interhemispheric coordination than with a specific left-hemispheric deficit in schizophrenia.

Lithium effects on normal subjects. Relationships to plasma and RBC lithium levels.

15 normal subjects took lithium carbonate for 10 days in dosage sufficient to attain plasma lithium concentrations in the range of 0.7-1.4 mEg/l. Periodic blood specimens were analyzed for both plasma and RBC lithium. Subjects completed Profile of Mood States questionnaires every other day, and listed side effects. Just prior to beginning and ending the lithium trial, 10 subjects completed three tests of psychomotor function. Results indicate that such a course of lithium in normals induces dysphoric mood change and psychomotor slowing, without significant relationship to either plasma or RBC lithium concentrations.

Patients' attitudes toward behavior therapy and psychotherapy.

A questionnaire survey of 50 patients treated by behavior therapy or short-term, analytically oriented psychotherapy revealed that both groups, as well as those patients who improved the most, placed a high value on insight, the patient-therapist relationship, catharsis, and trust. The findings suggest that behavior therapy patients tend to place more emphasis than do their therapists on factors that have traditionally been thought important in analytic psychotherapy.

Behavioural treatment of orgasmic dysfunction: a controlled study.

Twenty-two anorgasmic women received 20 sessions of a multiple-technique behavioural therapy. The design included blind ratings by two independent assessors, multiple assessment instruments, and a waiting list control group. Treatment was significantly better than no treatment in terms of: (1) the percentage of patients experiencing orgasm during at least 50 per cent of sexual relations; (2) the percentage of women reporting satisfactory sexual relations at least 50 per cent of the time; (3) patients' ratings of positive reactions to various sexual behaviours; and (4) assessors' global clinical ratings. Significant improvement was also noted on the MMPI, IPAT, and Symptom Check List. Improvement was maintained at a follow-up average 9 months later. These results support the impression that a behavioural approach offers much promise in treating female orgasmic dysfunction.

Auditory attention in process and reactive schizophrenia.

The present data indicate that, based on level of premorbid adjustment (process-reactive), schizophrenic subjects differ in auditory attention processes. Generally speaking, poor premorbid adjustment is associated with more attention dysfunction. Results also indicate that attentional deficits improve for all schizophrenic subjects after a 28-day period of neuroleptic therapy.

Differences between behavior therapists and psychotherapists.

Patient-therapist interaction patterns of three experienced behavior therapists and three matched analytically oriented therapists were compared. Each therapist saw ten patients in short-term individual therapy. The more active behavior therapists dominated the conversation in terms of speech time, more frequently offered explicit advice and instructions, gave more direct information, presented their own value judgments, and exerted greater control over the content of the interaction than did psychotherapists. Although both groups provided a warm and accepting atmosphere, behavior therapists showed higher levels of accurate empathy, interpersonal contact, and therapist self-congruence. Patients viewed behavior therapists as more authoritarian and believed that psychotherapists encourage greater independence. It was concluded that the two therapy approaches to patients were consistent with theoretical models of each.