Informal Subgroups Research Articles

Model of trust in work groups

A multi-dimensional model of trust in a small group has been developed and approved. This model includes two dimensions: trust levels (interpersonal trust, micro-group trust, group trust, trust between subgroups, trust between subgroups and group) and types of trust (activity-coping, information-influential and confidentially-protective trust). Each level of trust is manifested in three types, so there are fifteen varieties of trust. Two corresponding questionnaires were developed for the study. 347 persons from 32 work groups participated in the research. It was determined that in a small group there is an asymmetry of trust levels within the group. In particular, micro-group trust is demonstrated the most in comparison with other trust levels. There is also an asymmetry in the manifestation of interpersonal trust in a group structure. This is demonstrated by the fact that in informal subgroups, in comparison with a group as a whole, interpersonal confidential and performance trust is the most manifested. In a small group and in informal subgroups there are relationships between trust levels which have certain regularities.

A new terrestrial talitrid genus from the Philippine Islands (Crustacea, Amphipoda, Talitrida, Talitridae) and the designation of two informal subgroups

A new terrestrial talitrid genus from the Philippine Islands (Crustacea, Amphipoda, Talitrida, Talitridae) and the designation of two informal subgroups

A new terrestrial talitrid genus from the Philippine Islands (Crustacea, Amphipoda, Talitrida, Talitridae) and the designation of two informal subgroups

Curiotalitrus, a new genus of terrestrial land-hoppers (Amphipoda, Talitridae) is described from rain-forests in the Phil-ippines. Curiotalitrus includes one species: C. curioi (Javier & Coleman, 2010). Informal Talitrus and Orchestia groups are proposed based on the condition of the male second gnathopod.

A new species of Marphysa Quatrefages, 1865 (Polychaeta: Eunicida: Eunicidae) from northern Australia and a review of similar taxa from the Indo-west Pacific, including the genus Nauphanta Kinberg, 1865

A taxonomic survey of Marphysa species (Polychaeta: Eunicida: Eunicidae) from coastal regions of northern Australia including recently collected specimens from a fish farm near Darwin, yielded three species: M. mullawa Hutchings & Karageorgopolous, 2003, a first record from northern Australia; M. mossambica (Peters, 1854; was Nauphanta mossambica), first confirmed record from Australia; and a new species, M. fauchaldi. The new species was recorded from intertidal muddy shores as well as in the sediments of fish farm ponds, where it was extremely abundant. It is characterised by a unique combination of chaetal features. A newly proposed informal subgroup of Marphysa, the Teretiuscula-group, is erected to contain the new species and other Marphysa species that share the possession of compound spinigerous chaetae in anterior parapodia only and the peculiar behaviour of encapsulating embryos in jelly cocoons. Morphologically, the new species falls between a group of Marphysa species having only compound spinigers and the recently resurrected genus Nauphanta, which completely lacks compound chaetae. The discovery of this new species necessitated a re-evaluation of the morphological features of Nauphanta and Marphysa species lacking falcigers, in particular homology of fan chaetae, the only apparent synapomorphy of Nauphanta. Fan chaetae appear to be a specialised type of pectinate chaetae, which are found also in species of Marphysa including the new species. Based on this finding, and an evaluation of other characters, Nauphanta is returned to synonymy with Marphysa. Further, an analysis of size-related variation of key morphological characters in M. mossambica and comparison with those in the types of M. novaehollandiae (Kinberg, 1865; formerly Nauphanta) and M. simplex Treadwell, 1922, indicated that both species should be synonymised with M. mossambica. A key is provided to identify Marphysa species of the Indo-west Pacific.

A phylogenetic analysis of the genus Eunice (Eunicidae, polychaete, Annelida)

Species of Eunice are distributed worldwide, inhabiting soft and hard marine bottoms. Some of these species play significant roles in coral reef communities and others are commercially important. Eunice is the largest and most poorly defined genus in Eunicidae. It has traditionally been subdivided in taxonomically informal groups based on the colour and dentition of subacicular hooks, and branchial distribution. The monophyly of Eunice and of its informal subgroups is tested here using cladistic analyses of 24 ingroup species based on morphological data. In the phylogenetic hypothesis resulting from the present analyses Eunice and its subgroups are paraphyletic; the genus may be divided in at least two monophyletic groups, Eunice s.s. and Leodice, but several species do not fall inside these two groups. Most of the traditional characters used in the taxonomy of Eunice are homoplasies; however, characters used for the first time in this study, such as certain jaw characters and characters derived from a close examination of chaetal variation along the body, are promising sources of phylogenetic signal.

Reticulate evolution in the Acrolophus subgroup ( Centaurea L., Compositae) from the western Mediterranean: Origin and diversification of section Willkommia Blanca

Section Willkommia ( Centaurea, Compositae) is endemic to the east-central portion of the Iberian Peninsula and northwestern Africa. The section has been included with sections Acrolophus and Phalolepis in the informal subgroup Acrolophus. We have used a molecular phylogenetic approach to test the hypothesis proposed by earlier authors that the diversification of section Willkommia involved a schizoendemic process from an ancestral syngameon. Comparative analysis of the transcribed spacer sequences of the nuclear ribosomal DNA (ITS and 3′ETS) regions reveals the presence of three different types of ribosomal sequences in the Acrolophus subgroup (referred to here as the Willkommia, Acrolophus– Phalolepis and Simulans ribotypes) which show a sectional-independent geographic structure. This evidence, together with the presence of additive polymorphic sites in the Willkommia sequences which agree with the geographic distribution of the taxa, suggests that members of section Willkommia and the western Mediterranean taxa of sections Acrolophus and Phalolepis fit a reticulate evolution model.

Stamen Morphology in Nothofagus (Nothofagaceae)

Stamen morphology is shown to vary considerably in Nothofagus. All species in subgenus Brassospora have heteromorphic, striated epidermal papillae on their anthers. The absence of similar epidermal papillae in other subgenera in Nothofagus or in the putative sister taxa Fagaceae or Betulaceae would suggest that heteromorphic papillae is a derived feature in Brassospora. The anthers of the New Guinean taxa are heteromorphic in size, degree of connation, surface ornamentation, and in the variable position of papillae. This variation permits recognition of a number of informal subgroups in the New Guinean species of Brassospora. The anthers of all the New Caledonian species are large to very large in size and have a similar ornamentation, which differs from that in the New Guinean species. All Brassospora species also have connate stamen filaments, which is a possible synapomorphy for the subgenus, which does not occur in the other three subgenera, or in the Fagaceae and Betulaceae. Rounded isomorphic papillae occur on the epidermal cells of the stamens in three species of subgenus Lophozonia; N. nervosa and N obliqua from South America, and N. moorei from Australia. The absence of this type of papillae from other species in Lophozonia and other subgenera in Nothofagus and putative outgroups would suggest that single papilla is a derived feature in this subgenus. The similar anther ornamentation in N. obliqua and N. nervosa, i.e, solitary papillae with basal striations, suggests that they are sister taxa. Nothofagus moorei also has solitary papillae but lacks the basal striations seen in the South American taxa. This taxon is either sister to the South American species, or, alternatively, single papillae have arisen independently in these two groups in Lophozonia. The variation in stamen morphology in Nothofagus allows for the recognition of a number of anther and filament characters that appear to be of phylogenetic significance.

Integrating the Desegregated School

It is self-defeating for a school staff to attempt to destroy informal student subgroup organizations, believes this author. He gives suggestions for helping minority groups to become more cohesive with the student body.