Object-oriented cohesion as a surrogate of software comprehension: An empirical study

The concept of software cohesion in both the procedural and object-oriented paradigm is well known and documented. What is not so well known or documented is the perception of what empirically constitutes a cohesive 'unit' by software engineers. In this paper, we describe an empirical investigation using object-oriented (OO) classes as a basis. Twenty-four subjects (drawn from IT experienced and IT inexperienced groups) were asked to rate ten classes sampled from two industrial systems in terms of their overall cohesiveness; a class environment was used to carry out the study. Four key results were observed. Firstly, class size (when expressed in terms of number of methods) did not tend to influence the perception of cohesion by any subjects. Secondly, well-commented classes were rated most highly amongst both IT experienced and inexperienced subjects. Thirdly, the empirical study suggests that cohesion comprises a combination of various class factors including low coupling, small numbers of attributes and well-commented methods, rather than any single, individual class feature per se. Finally, the research supports the view that cohesion is a subjective concept reflecting a cognitive combination of class features; as such it is a surrogate for class comprehension

Lattice Boltzmann simulations of lamellar and droplet phases

Lattice Boltzmann simulations are used to investigate spinodal decomposition in a two-dimensional binary fluid with equilibrium lamellar and droplet phases. We emphasise the importance of hydrodynamic flow to the phase separation kinetics. For mixtures slightly asymmetric in composition the fluid phase separates into bulk and lamellar phases with the lamellae forming distinctive spiral structures to minimise their elastic energy.Comment: 19 pages, 5 figure

The role of law and ethics in developing business management as a profession

Currently, business management is far from being recognised as a profession. This paper suggests that a professional spirit should be developed which could function as a filter of commercial reasoning. Broadly, management will not be organised within the framework of a well-established profession unless formal knowledge, licensing, professional autonomy and professional codes of conduct are developed sufficiently. In developing business management as a profession, law may play a key role. Where the idea is that business management should be more professsionalised, managers must show that they are willing to adopt ethical values, while arriving at business decisions. The paper argues that ethics cannot survive without legal regulation, which, in turn, will not be supported by law unless lawyers can find alternative solutions to the large mechanisms of the official society, secured by the monopolised coercion of the nation state. From a micro perspective of law and business ethics, communities can be developed with their own conventions, rules and standards that are generated and sanctioned within the boundaries of the communities themselves

Concentric cracking of grape berries

Light microscopy has been used to study the anatomy of "cracks" and "splits" in grape berries. In cracking, fine concentric surface cracks in the skin are formed around the base of the pedicel or at the stylar end. Cracks usually involved rupture of the cuticle and epidermal layer of cells only. In splitting, the cuticle, epidermis, sub-epiclermis and outer pericarp cells were ruptured. Suberization was evident in the cells beneath cracks, but was not present in the cells around splits. Possible mechanisms of epidermal damage and penetration of microorganisms are discussed in relation to cracking ancl splitting.Konzentrisches Aufreißen von WeinbeerenBei Traubenbeeren wurden Schrunden (,,cracks") und Platzwunden (,,splits") beobachtet, deren anatomische Verhältnisse lichtmikroskopisch untersucht wurden. Die Schrunden bilden sich als feine, konzentrische Oberflächenrisse um den Beerenansatz oder am apikalen Ende der Beere. In diesem Falle sind gewöhnlich nur die Kutikula und die epidermale Zellschicht aufgerissen. Die Platzwunden erstrecken sich dagegen auf Kutikula, Epidermis, Subepidermis und die äußeren Perikarpzellen. In den Zellen unterhalb der Schrunden ließ sich Verkorkung nachweisen, nicht jedoch in den an die Platzwunden angrenzenden Zellen. Mechanismen, die für die Beschädigung der Epidermis verantwortlich sein könnten, sowie das Eindringen von Mikroorganismen werden im Zusammenhang mit dem Auftreten von Schrunden und Platzwunden diskutiert

Scaling of the Random-Field Ising Model at Zero Temperature

The exact determination of ground states of small systems is used in a scaling study of the random-field Ising model. While three variants of the model are found to be in the same universality class in 3 dimensions, the Gaussian and bimodal models behave distinctly in 4 dimensions with the latter apparently having a discontinuous jump in the magnetization. A finite-size scaling analysis is presented for this transition.Comment: 14 pages Latex, 4 figure

Decomposition of coarse woody debris in a long-term litter manipulation experiment: A focus on nutrient availability

The majority of above-ground carbon in tropical forests is stored in wood, which is returned to the atmosphere during decomposition of coarse woody debris. However, the factors controlling wood decomposition have not been experimentally manipulated over time scales comparable to the length of this process.We hypothesized that wood decomposition is limited by nutrient availability and tested this hypothesis in a long-term litter addition and removal experiment in a lowland tropical forest in Panama. Specifically, we quantified decomposition using a 15-year chronosequence of decaying boles, and measured respiration rates and nutrient limitation of wood decomposer communities.The long-term probability that a dead tree completely decomposed was decreased in plots where litter was removed, but did not differ between litter addition and control treatments. Similarly, respiration rates of wood decomposer communities were greater in control treatments relative to litter removal plots; litter addition treatments did not differ from either of the other treatments. Respiration rates increased in response to nutrient addition (nitrogen, phosphorus, and potassium) in the litter removal and addition treatments, but not in the controls.Established decreases in concentrations of soil nutrients in litter removal plots and increased respiration rates in response to nutrient addition suggest that reduced rates of wood decomposition after litter removal were caused by decreased nutrient availability. The effects of litter manipulations differed directionally from a previous short-term decomposition study in the same plots, and reduced rates of bole decomposition in litter removal plots did not emerge until after more than 6 years of decomposition. These differences suggest that litter-mediated effects on nutrient dynamics have complex interactions with decomposition over time

Fate of Captive-Reared and Released Mallards on Eastern Long Island, New York

We studied captive-reared mallards (Anas platyrhynchos; CRMs) released on eastern Long Island, New York, in 2006 to 2007 and 2007 to 2008 to determine: (1) survival rates of CRMs; (2) contribution to hunter harvest; (3) local movements; and (4) pair status, reproductive behavior, and production of CRMs. We banded and released 100 CRMs in November 2006 of which 20 were radio-marked. In November 2007, we banded and released 299 CRMs of which 60 were radio-marked. We used Program MARK to determine weekly survival estimates (0.53 to 1.00) up to 24 weeks after release; cumulative survival from November to May was 0.25. Seventeen percent (n = 17) of CRMs were reported harvested from 2006 to 2007, and 5% (n = 15) were reported harvested during 2007 to 2008. The median distance between harvest locations and release sites in both years was 3 km. CRMs intermingled with free-ranging waterfowl at town parks but tended to stay together in groups of 10 to 30 birds. We observed 22 pairs of CRMs, 2 pairs of CRMs with unmarked mallards, and 1 CRM with a brood. Overall, our data indicated that after some initial losses, many CRMs survived and settled in park settings where waterfowl were commonly fed by humans. Thus, CRMs appeared to contribute to feral waterfowl populations, which are a source of human–wildlife conflicts in many areas. Occurrence of CRMs in such settings also provides a means for disease transmission to free-ranging waterfowl

Control Of Norway Rats In Sewer And Utility Systems Using Pulsed Baiting Methods

There were 1,288 sewer and 235 other utility manholes baited to control Norway rat (Rattus norvegicus) populations in downtown Boston using pulsed-baiting methods. About 15% of all sewer, 18% of phone, and 26% of electric manholes had rat activity. Sewer populations were most associated with residential areas with low flow, small diameter (\u3c61 cm) brick sewers; in those circumstances, up to 38% of manholes had rat activity. Bait consumption in sewers (high risk areas) was 91 % below baseline, five months after the fourth baiting period. Bait consumption and the number of active sewer holes were 96% and 87% below baseline, respectively, when seasonal maintenance baiting was last initiated. Reinfestation of phone/electric manholes was so minimal that maintenance baiting was not necessary or cost-effective. Subsurface baiting should be an integral part of urban rodent control programs

Holding back the tears: individual differences in adult crying proneness reflect attachment orientation and attitudes to crying

Despite being a universal human attachment behavior, little is known about individual differences in crying. To facilitate such examination we first recommend shortened versions of the attitudes and proneness sections of the Adult Crying Inventory using two independent samples. Importantly, we examine attachment orientation differences in crying proneness and test the mediating role of attitudes toward crying in this relationship. Participants (Sample 1 N=623, Sample 2 N=781), completed online measures of adult attachment dimensions (avoidance and anxiety), attitudes towards crying, and crying proneness. Exploratory factor analyses in Sample 1 revealed four factors for crying attitudes: crying helps one feel better; crying is healthy; hatred of crying; and crying is controllable; and three factors for crying proneness: threat to self; sadness; and joy. Confirmatory factor analyses in Sample 2 replicated these structures. Theoretically and statistically justified short forms of each scale were created. Multiple mediation analyses revealed similar patterns of results across the two samples, with the attitudes ‘crying is healthy’ and ‘crying is controllable’ consistently mediating the positive links between attachment anxiety and crying proneness, and the negative links between attachment avoidance and crying proneness. Results are discussed in relation to attachment and emotion regulation literature