Effects of urbanization on the aquatic fauna of the Line Creek watershed, Atlanta—a satellite perspective

Impervious surface area (ISA) was derived for a period from 1979 to 1997 from Landsat MSS and TM data for the Line Creek watershed that lies to the south of the city of Atlanta, GA. The change in ISA is presented as an ecological indicator to examine the cumulative water resource impacts on mussel population in three sub-watersheds of Line Creek—namely, Line, Flat, and Whitewater creeks. The satellite analysis shows that ISA expansion occurred substantially from 1987 to 1997 and is predominantly in industrial, commercial, and shopping center (ICS) complexes but also in smaller lot-size residential development. Evidence of mussel habitat degradation is indicated and loss of species (in the region of 50 to 70%) is present in areas where ISA expansion is observed—specifically in ICS complex development in and around Peachtree City that drains directly into the Line and Flat creeks. This is in marked contrast to Whitewater Creek where overall development of ISA is less and no major loss of mussel species is observed.     

Rectus abdominis muscle flap (RAMF) technique for the management of bladder exstrophies: late clinical outcome and urodynamic findings

OBJECTIVE: To investigate the efficacy of the rectus abdominis muscle flap (RAMF) technique for the closure and augmentation of small, non-compliant bladder exstrophies. PATIENTS AND METHODS: The RAMF technique was used in two girls and two boys (mean age at operation, 31.7 months, range 3-72) with bladder exstrophy. The clinical outcome and urodynamics were assessed during a follow-up of 29 months to 6 years (mean 49.2 months) and included imaging, cystoscopy, biochemical and microbiological studies. RESULTS: There were no urinary tract infections, metabolic problems or electrolyte disturbances and kidney function remained normal in all patients. Radiography confirmed intact function and anatomy of the urinary tract and cystoscopy showed complete coverage of the inner peritoneal layer of RAMF with uroepithelium. No stone formation or mucus production were detected. Currently, three patients void using clean intermittent catheterization through the native urethra and the fourth through an appendiceal Mitrofanoff valve. However, the bladder volume was insufficient at the late follow-up and three patients required bladder augmentation. CONCLUSIONS: The RAMF technique is a good alternative for closing bladder exstrophies and achieves an increase in bladder capacity; however, although there is a mild improvement in bladder capacity and compliance. RAMF should not be used as a bladder augmentation procedure. The technique is indicated in the closure of large bladder defects, bladder exstrophies with small, inelastic, non-compliant bladder remnants and failed primary closures.     

Pruning Algorithms for Rule Learning

Pre-pruning and Post-pruning are two standard techniques for handling noise in decision tree learning. Pre-pruning deals with noise during learning, while post-pruning addresses this problem after an overfitting theory has been learned. We first review several adaptations of pre- and post-pruning techniques for separate-and-conquer rule learning algorithms and discuss some fundamental problems. The primary goal of this paper is to show how to solve these problems with two new algorithms that combine and integrate pre- and post-pruning.     

Inefficiency of lactation in primiparous rats: the costs of first reproduction

To investigate the energetic costs of lactation in a female mammal in relation to previous reproductive history, we compared the performance of adult female Long-Evans rats that had previously bred (multiparous) with young females that had not previously given birth (primiparous). All litters were standardized to 10 +/- 1 young. We compared maternal production (growth of pups), body mass, and energy intake (food consumption) of mothers, as well as their energy expenditure (resting oxygen consumption). The mass of litters at birth and the growth of pups during lactation did not differ according to reproductive history of the mothers. The body mass of primiparous mothers was less than that of multiparous mothers, and primiparous mothers showed an increase in mass during early lactation. To accomplish the essentially identical production of offspring under these circumstances, the primiparous mothers consumed and expended more energy than the multiparous mothers. This remarkable performance of first-time mothers results in an overall efficiency of energy allocation to reproduction amounting to only 25%, compared with 38% in multiparous mothers. The energetic inefficiency of primiparous female lactation results largely from the excessive expenditures associated with physiological and behavioral performances of first-time reproduction, together with a small component of additional expenditure due to further growth by the primiparous mothers. We suggest that this inefficiency probably contributes to the observed low reproductive success of novice breeders; furthermore, active restraint of fecundity may be an evolutionary response to the constraints of the energetic inefficiency of primiparous breeding by female mammals.     

Pseudoexfoliation syndrome and secondary cataract

AIM/BACKGROUND: The pseudoexfoliation (PEX) syndrome is frequently associated with impairment of the blood-aqueous barrier. This study analysed if this might stimulate secondary cataract following cataract extraction. METHODS: This historical cohort study included 197 eyes of 197 patients (99 with and 98 without PEX) that underwent extracapsular cataract extraction with posterior chamber lens implantation (PMMA optic) between 1985 and 1991. Secondary cataract was defined as opacification of the axial posterior capsule and decrease of visual acuity by two or more lines. Mean follow up was 23.8 months. For statistical analysis, the Kaplan-Meier method and multivariate Cox regression analysis were used. RESULTS: Secondary cataract was observed within 24 months in 35% (SD 7%) of all eyes, and was significantly more frequent in eyes with PEX (45 (11)%) than in eyes without PEX (24 (9)%, p < 0.03). Eyes with diabetes mellitus (n = 32) showed a significantly lower frequency of secondary cataract (11 (11)%) than eyes without diabetes mellitus (39 (8)%, p < 0.01). The influences of sex, open angle glaucoma, type of cataract, surgeon, positioning of IOL, and phacoemulsification versus nuclear expression on secondary cataract did not reach statistical significance. CONCLUSION: The higher frequency of secondary cataract could be considered as another potential complication of cataract surgery in eyes with PEX.     

The relationship between umbilical artery Doppler findings, fetal biophysical score and placental inflammation in cases of premature rupture of membranes

BACKGROUND: To assess the relationship between placental inflammation, umbilical artery Doppler waveforms and fetal biophysical profile score, umbilical artery Doppler studies and fetal biophysical evaluations were performed in 24 preterm pregnants with premature rupture of membranes (PPROM). SUBJECTS: After delivery, the placentas were microscopically examined and two subgroups were formed including noninflamed or inflamed placentas. RESULTS: In the first group, which includes 14 cases with no histological signs of placental inflammation, we found increased systolic/diastolic ratio only in one patient, whereas in the second group including ten cases with microscopically proven inflammation, nine were found to have increased systolic/diastolic ratios (p < 0.05). Mean systolic/diastolic ratio in the first and the second groups were 2.74 +/- 0.18 and 4.64 +/- 0.93 respectively (p < 0.001). Mean biophysical profile score was 9 +/- 1.04 in the first group and 7 +/- 1.05 in the second group (p < 0.001). CONCLUSION: Abnormal biophysical profile scores along with increased arterial systolic/diastolic ratios have been shown to be the markers of impending clinical infection.     

Expression and molecular characterization of an enzymatically active recombinant human spumaretrovirus protease

A theoretical model is presented by which a true expression of pregnancy rate resulting from stimulated cycles can be calculated. This includes the transfer of both fresh and cryopreserved embryos. It is concluded that the total reproductive potential of a single cycle of stimulation can only be evaluated by including pregnancies arising from all fresh and frozen embryo transfers resulting from that cycle.