Phytoplanktonic community and bio-optical properties in coastal waters of an Argentinian Patagonian gulf.

The influence of the phytoplankton community in the light absorption budget was quantified in coastal waters of the North region of the San Jorge Gulf (Argentinian Patagonia). The phytoplanktonic composition and their absorption spectra were determined. Nanoflagellates and diatoms were the dominant groups. The toxigenic dinoflagellate Dinophysis acuminata was recorded in all the sampling sites. The optical characterization of the particulate material showed that 60 % of the absorption at 443 nm and 88 % of absorption at 675 nm was due to phytoplankton. The contributions of phytoplankton to total absorption at 443 nm wavelengths reached 50 %. The absorption by chromophoric dissolved organic matter (CDOM) and non-algal particles (NAP) was predominant in turbulent waters (>60 %). This study shows the influence of submesoscale physical-biological interactions in the light absorption budget. The field absorption spectra of active optical components are of interest in the assessment and development of regional ocean color satellite algorithms.

Dynamic knee stability: current theory and implications for clinicians and scientists.

We will discuss the mechanisms by which dynamic knee stability may be achieved and relate this to issues that interest clinicians and scientists concerned with dynamic knee stability. Emphasis is placed on the neurophysiologic evidence and theory related to neuromuscular control. Specific topics discussed include the ensemble firing of peripheral mechanoreceptors, the potential for muscle stiffness modulation via force and length feedback, postural control synergies, motor programs, and the neural control of gait. Factors related to answering the difficult question of whether or not knee ligament injuries can be prevented during athletic activities are discussed. Prevention programs that train athletes to perform their sport skills in a safe fashion are put forth as the most promising prospect for injury prevention. Methods of assessing neuromuscular function are reviewed critically and the need for future research in this area is emphasized. We conclude with a brief review of the literature regarding neuromuscular training programs.

Host-guest-like thiamine-anion complexation in thiaminium bis(tetrafluoroborate).

In the title compound, 3-[(4-amino-2-methyl-5-pyrimidin-1-io)methyl]-5-(2-hydroxyethyl)-4-methylthiazolium(2+) bis(tetrafluoroborate), C(12)H(18)N(4)OS(2+).2BF(4)(-), the divalent thiamine cation (in the F conformation) is associated with BF(4)(-) anions via two characteristic bridging interactions between the thiazolium and pyrimidinium rings, i.e. C-H...BF(4)(-)...pyrimidinium and N-H...BF(4)(-)...thiazolium interactions. Thiamine molecules are linked by N-H...O hydrogen bonds to form a helical chain structure.

Comparison of the single assessment numeric evaluation method and the Lysholm score.

The purpose of this study was to determine the correlation between the Lysholm knee score and the Single Assessment Numeric Evaluation method. Between March 1995 and December 1996, 201 followup examinations were performed on 130 college age patients who had undergone anterior cruciate ligament reconstructions. These 201 examinations were divided into five routine followup categories: 3 months, 6 months, 1 year, 2 years, and greater than 2 years. The Lysholm score from each patient's followup questionnaire was correlated with his or her Single Assessment Numeric Evaluation rating, as determined by his or her written response to the following question: On a scale from zero to 100, how would you rate your knee today (100 being normal)? All data were gathered prospectively. The mean Lysholm scores and Single Assessment Numeric Evaluation ratings ranged from 84.0 to 93.4 points and 80.0 to 93.3 points, respectively. The correlation coefficients between the Lysholm scores and the Single Assessment Numeric Evaluation ratings ranged from 0.58 to 0.87 points. The results of this study indicate that Single Assessment Numeric Evaluation ratings correlate well with measured Lysholm scores in patients with anterior cruciate ligament reconstruction. The Single Assessment Numeric Evaluation provides clinicians with an alternative mechanism to gather outcomes data with little demand on time and resources.

Comparison of the Single Assessment Numeric Evaluation method and two shoulder rating scales. Outcomes measures after shoulder surgery.

The purpose of this study was to determine the correlation between the Single Assessment Numeric Evaluation method and the Rowe and American Shoulder and Elbow Surgeons scores. Between April 1993 and December 1996, 209 follow-up examinations were performed on 163 United States Military Academy cadets after shoulder surgery. These 209 examinations were divided into five follow-up categories: 3 months, 6 months, 1 year, 2 years, and greater than 2 years. The Rowe and American Shoulder and Elbow Surgeons scores from each subject's follow-up questionnaire were correlated with his or her Single Assessment Numeric Evaluation rating, which is determined by the subject's written response to the following question: "How would you rate your shoulder today as a percentage of normal (0% to 100% scale with 100% being normal)?" Correlation coefficients between the Single Assessment Numeric Evaluation and the two scores were 0.51 to 0.79 for the Rowe score and 0.46 to 0.69 for the American Shoulder Elbow Surgeons score. The results of this study indicate that the Single Assessment Numeric Evaluation correlates well with these two scores after shoulder surgery. This study suggests that this new evaluation method provides clinicians with a mechanism to gather outcomes data with little demand on their time and resources.

Persistent disability associated with ankle sprains: a prospective examination of an athletic population.

The purpose of this study was to examine a young athletic population to update the data regarding epidemiology and disability associated with ankle injuries. At the United States Military Academy, all cadets presenting with ankle injuries during a 2-month period were included in this prospective observational study. The initial evaluation included an extensive questionnaire, physical examination, and radiographs. Ankle sprain treatment included a supervised rehabilitation program. Subjects were reevaluated at 6 weeks and 6 months with subjective assessment, physical examination, and functional testing. The mean age for all subjects was 20 years (range, 17-24 years). There were 104 ankle injuries accounting for 23% of all injuries seen. There were 96 sprains, 7 fractures, and 1 contusion. Of the 96 sprains, 4 were predominately medial injuries, 76 were lateral, and 16 were syndesmosis sprains. Ninety-five percent had returned to sports activities by 6 weeks; however, 55% of these subjects reported loss of function or presence of intermittent pain, and 23% had a decrement of >20% in the lateral hop test when compared with the uninjured side. At 6 months, all subjects had returned to full activity; however, 40% reported residual symptoms and 2.5% had a decrement of >20% on the lateral hop test. Neither previous injury nor ligament laxity was predictive of chronic symptomatology. Furthermore, chronic dysfunction could not be predicted by the grade of sprain (grade I vs. II). The factor most predictive of residual symptoms was a syndesmosis sprain, regardless of grade. Syndesmosis sprains were most prevalent in collision sports. This study demonstrates that even though our knowledge and understanding of ankle sprains and rehabilitation of these injuries have progressed in the last 20 years, chronic ankle dysfunction continues to be a prevalent problem. The early return to sports occurs after almost every ankle sprain; however, dysfunction persists in 40% of patients for as long as 6 months after injury. Syndesmosis sprains are more common than previously thought, and this confirms that syndesmosis sprains are associated with prolonged disability.