Software assessment using metrics: A comparison across large C++ and Java systems

This paper presents an assessment method to evaluate the quality of object oriented software systems. The assessment method is based on source code abstraction, object–oriented metrics and graphical representation. The metrics used and the underlying model representing the software are presented. The assessment method experiment is part of an industrial research effort with the Bell Canada Quality Engineering and Research Group. It helps evaluators assess the quality and risks associated with software by identifying code fragments presenting unusual characteristics. The assessment method evaluates object–oriented software systems at three levels of granularity: system level, class level and method level. One large C++ and eight Java software systems, for a total of over one million lines of code, are presented as case studies. A critical analysis of the results is presented comparing the systems and the two languages.     

Relationship of passive cigarette-smoking to sudden infant death syndrome

The smoking habits of 56 families who lost babies to the sudden infant death syndrome (SIDS) were compared to those of 86 control families. A higher proportion of SIDS mothers smoked both during pregnancy (61% vs. 42%) and after their babies were born (59% vs. 37%). SIDS mother also smoked a significantly greater number of cigarettes than controls. Exposure to cigarette smoke ("passive smoking") appears to enhance the risk of SIDS for reasons not known.     

Thyroid cancer after exposure to external radiation: a pooled analysis of seven studies

The thyroid gland of children is especially vulnerable to the carcinogenic action of ionizing radiation. To provide insights into various modifying influences on risk, seven major studies with organ doses to individual subjects were evaluated. Five cohort studies (atomic bomb survivors, children treated for tinea capitis, two studies of children irradiated for enlarged tonsils, and infants irradiated for an enlarged thymus gland) and two case-control studies (patients with cervical cancer and childhood cancer) were studied. The combined studies include almost 120,000 people (approximately 58,000 exposed to a wide range of doses and 61,000 nonexposed subjects), nearly 700 thyroid cancers and 3,000,000 person years of follow-up. For persons exposed to radiation before age 15 years, linearity best described the dose response, even down to 0.10 Gy. At the highest doses (> 10 Gy), associated with cancer therapy, there appeared to be a decrease or leveling of risk. For childhood exposures, the pooled excess relative risk per Gy (ERR/Gy) was 7.7 (95% CI = 2.1, 28.7) and the excess absolute risk per 10(4) PY Gy (EAR/10(4) PY Gy) was 4.4 (95% CI = 1.9, 10.1). The attributable risk percent (AR%) at 1 Gy was 88%. However, these summary estimates were affected strongly by age at exposure even within this limited age range. The ERR was greater (P = 0.07) for females than males, but the findings from the individual studies were not consistent. The EAR was higher among women, reflecting their higher rate of naturally occurring thyroid cancer. The distribution of ERR over time followed neither a simple multiplicative nor an additive pattern in relation to background occurrence. Only two cases were seen within 5 years of exposure. The ERR began to decline about 30 years after exposure but was still elevated at 40 years. Risk also decreased significantly with increasing age at exposure, with little risk apparent after age 20 years. Based on limited data, there was a suggestion that spreading dose over time (from a few days to > 1 year) may lower risk, possibly due to the opportunity for cellular repair mechanisms to operate. The thyroid gland in children has one of the highest risk coefficients of any organ and is the only tissue with convincing evidence for risk about 1.10 Gy.     

The role of cytotoxic chemotherapy in the management of aggressive and malignant pituitary tumors

Pituitary tumors are mostly benign lesions, although 5-35% are locally invasive. A small number exhibit a more aggressive course, infiltrating dura, bone and sinuses, and are designated highly aggressive. However, the presence of metastases separate from the pituitary in the central nervous system or at a distance is necessary to designate pituitary tumors as carcinomas, i.e. truly malignant. When conventional therapeutic modalities fail, systemic chemotherapy remains the last option. We report seven such patients, three with highly aggressive and four with malignant pituitary tumors (n=4) four women; median age, 32 yr; range, 23-48 yr), who received one or more courses of chemotherapy with lomustine and 5-fluorouracil (median, two courses; range, one to six courses). Three patients with systemic metastatic disease had a shorter survival (median, 5 months; range, 1-14 months) than the one patient with central nervous system metastases alone (10 yr). A patient with an aggressive nonmetastatic prolactinoma who initially responded to chemotherapy died from another nondisease-associated cause. Two patients, one with an aggressive and one with a metastatic tumor, achieved symptomatic improvement with a median duration of 6 months. A hormonal reduction greater than 50% was observed in two of seven patients; only one patient who had an aggressive tumor obtained an objective tumor response. The median survival from the time of initiation of chemotherapy in patients with malignant tumors ranged from 3-65 months. Two patients with malignant tumors developed disease progression while receiving chemotherapy; no patient with extracranial metastases showed a response. Treatment was well tolerated, with minimal individual side-effects. Three patients with no response to initial treatment received different chemotherapeutic regimens with no additional response. All patients with metastatic malignant tumors eventually died. Treatment with cytotoxic chemotherapy is noncurative, and current experience is limited. Until another more specific form of treatment is available, chemotherapy may still be of some value in patients with highly aggressive and malignant pituitary tumors, at least in achieving a temporary remission or delay in progression. The combination of lomustine/5-fluorouracil proved easy to administer with minimal toxicity, although the response rate was only 14%. Until a more specific treatment is found, an optimal chemotherapeutic regimen needs to be established.     

Testing of "Venetian-Blind" silicon microstructures with optical methods

In this paper, we illustrate the design and testing of new silicon microstructures, fabricated by means of a conventional planar process. These "Venetian-blind" structures consist of arrays of narrow, rectangular suspended masses (width =31 /spl mu/m, length =400 /spl mu/m, thickness =15 /spl mu/m), which can be tilted using electrostatic actuation. Characterization of their static and dynamic behavior was performed with optical methods. The diffraction patterns in monochromatic light were analyzed and vibration measurements were performed by means of semiconductor laser feedback interferometry: experimental data on the tilt angle as a function of the applied voltage and on the resonance frequencies are reported. A maximum tilt angle of approximately 1.9/spl deg/ was obtained with a driving voltage in the range of 70-95 V. All the tested devices showed resonance frequencies higher than 80 kHz, which is fast enough (i.e., switching time in the millisecond range) for future use in optical interconnections. Numerical analyses were performed to evaluate the coupled electromechanical behavior of the microstructures, confirming the observed experimental behavior.     

Wound fluids and the pathogenesis of chronic wounds

PURPOSE: To describe two areas of ongoing investigation into analysis of wound fluids that may eventually lead to better understanding of pathophysiology of chronic wounds and to improved care and treatment. METHODS: Studies used Lowry protein assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting, and zymography to analyze fluids from acute and chronic wounds and serum samples collected from healthy and affected volunteers. SUBJECTS: Thirty-one subjects with ages ranging from 32 to 79 years participated in the research; fluid was collected from chronic wounds in 10 patients (two female, four male, and four unrecorded), fluid was collected from acute mastectomy wounds in 15 patients (all female); blister fluid and blood were collected from two volunteers (one male, one female); and blood for serum preparation was collected from four volunteers (two female, two male). PRIMARY OUTCOME VARIABLES: (1) Fibronectin degradation and (2) expression of matrix metalloproteinases. RESULTS: Fibronectin can be degraded in fluid from chronic wounds but remains intact in blood-derived serum, plasma-derived serum, blister fluid, and mastectomy wound fluid. Matrix metalloproteinases are overexpressed in fluid from chronic wounds compared with mastectomy wound fluid, blood-derived serum, and plasma-derived serum. Matrix metalloproteinases are also expressed of somewhat higher levels in mastectomy fluid than in blood-derived and plasma-derived serum. CONCLUSIONS: These studies identified two factors that may contribute to delayed healing of chronic wound: fibronectin degradation and overexpression of matrix metalioproteinases.     

Peptide amidating activity in human bronchoalveolar lavage fluid

Monitoring respiratory epithelial biology may reveal individuals with incipient lung cancer. The expression of neuroendocrine (NE) markers in pulmonary epithelium is thought to be central to lung development, repair of injury and may contribute to carcinogenesis. In this study, we evaluate several candidate NE markers to determine the feasibility of prospective analysis of clinical specimens. The potential NE markers include the enzyme L-DOPA decarboxylase (DDC), the neuropeptide gastrin releasing peptide (GRP), and peptidyl-glycine alpha-amidating monooxygenase (PAM), the bifunctional enzyme responsible for the final bioactivation step of many neuropeptides. A comparison of PAM activity and DDC levels in 30 lung cancer cell lines indicated that peptide amidating activity may be an indicator of NE status. Bronchoalveolar lavage (BAL) fluid from subjects at risk of developing second primary lung cancer and from volunteers was obtained. The activity of the first PAM enzyme, peptidylglycine alpha-hydroxylating monooxygenase (PHM), ranged from not detectable to 507 pmol/h/mg protein in 57 specimens. The second PAM enzyme, peptidylamidoglycolate lyase (PAL), ranged from not detectable to 414 pmol/h/mg protein in 56 specimens. Using cluster analysis by the average linkage method, a group of enzyme values with PHM greater than 230 pmol/h/mg protein was determined. Long-term follow-up of these patients for new second primary lung cancers may help to determine the potential predictive value of PAM detected in the BAL fluid.     

A novel phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase associates with the interleukin-3 receptor

To gain insight into the intracellular signaling cascades that are activated by the binding of interleukin-3 (IL-3) to its target cells, we have embarked on the identification of proteins that are associated with the IL-3 receptor (IL-3R). In a previous study we reported that a 110-kDa serine/threonine protein kinase is constitutively associated with the IL-3R and activated following IL-3 stimulation. We now report that a phosphatidylinositol-3,4, 5-trisphosphate (PtdIns-3,4,5-P3) 5-phosphatase (5-ptase) is also constitutively associated with the IL-3R. This 5-ptase is magnesium-dependent and removes the 5-position phosphate from PtdIns-3,4,5-P3 but does not metabolize PtdIns-4,5-P2, inositol (Ins)-1,3,4,5-P4, or Ins-1,4,5-P3. This substrate specificity distinguishes it from any previously characterized 5-ptase. Interestingly, it may be bound indirectly via phosphatidylinositol 3-kinase (PI 3-kinase), another enzyme that is constitutively bound to the IL-3R. However, unlike PI 3-kinase which becomes activated following IL-3 stimulation, this receptor-associated 5-ptase activity does not increase following IL-3 stimulation, and its primary function may be to keep the principal in vivo product of PI 3-kinase, PtdIns-3,4,5-P3, at low levels in unstimulated cells, to terminate the PI 3-kinase signal following IL-3 stimulation or to metabolize PtdIns-3,4,5-P3 to a metabolically active second messenger, i.e. PtdIns-3,4-P2.