Caste Development and Its Seasonal Cycle in the Australian Harvester Termite, Drepanotermes Perniger (Froggatt) (Isoptera; Termitinae).

1974 ◽  
Vol 22 (4) ◽  
pp. 471 ◽  
Author(s):  
JAL Watson
Keyword(s):  
Seasonal Cycle ◽  
Early Summer ◽  
Fourth Instar ◽  
Northern Australia ◽  
The South ◽  
Worker Characteristics ◽  
Caste Development ◽  
Single Worker

The development of Drepanotermes perniger (Frogg.) in Australia is simple, with non-reproductive and reproductive lines separating at the first moult, a single worker line, a monomorphic soldier caste derived from two or three worker stages, and brachypterous neotenics formed by the premature metamorphosis of fifth-instar reproductive nymphs. Intercastes are known between soldier and fifth-instar reproductive nymph; presoldier and neotenic; and third-instar worker and fourth-instar reproductive nymph. All have substantially nymphal thoraces and abdomens, with minor intercaste modifications, and heads that are variously modified from nymphal towards soldier, presoldier or worker characteristics. The development of the castes shows a marked seasonal cycle, and only workers, soldiers and fourth-instar reproductive nymphs occur during the winter. Oviposition begins after the resumption of foraging in spring, and in the south growth and differentiation continue through much of the summer. Fourth-instar nymphs break diapause synchronously in early summer, and the alates fly with rains in January or February. In northern Australia there is a break in oviposition during summer, and the reproductive nymphs develop from eggs laid in autumn, after the alates have flown.

scholarly journals Nonstationarity in Southern Hemisphere Climate Variability Associated with the Seasonal Breakdown of the Stratospheric Polar Vortex

2017 ◽  
Vol 30 (18) ◽  
pp. 7125-7139 ◽  
Author(s):  
Nicholas J. Byrne ◽  
Theodore G. Shepherd ◽  
Tim Woollings ◽  
R. Alan Plumb
Keyword(s):  
Climate Variability ◽  
Southern Hemisphere ◽  
Seasonal Cycle ◽  
Vortex Breakdown ◽  
Polar Vortex ◽  
Reanalysis Data ◽  
Early Summer ◽  
Stratospheric Polar Vortex ◽  
Time Symmetry

Abstract Statistical models of climate generally regard climate variability as anomalies about a climatological seasonal cycle, which are treated as a stationary stochastic process plus a long-term seasonally dependent trend. However, the climate system has deterministic aspects apart from the climatological seasonal cycle and long-term trends, and the assumption of stationary statistics is only an approximation. The variability of the Southern Hemisphere zonal-mean circulation in the period encompassing late spring and summer is an important climate phenomenon and has been the subject of numerous studies. It is shown here, using reanalysis data, that this variability is rendered highly nonstationary by the organizing influence of the seasonal breakdown of the stratospheric polar vortex, which breaks time symmetry. It is argued that the zonal-mean tropospheric circulation variability during this period is best viewed as interannual variability in the transition between the springtime and summertime regimes induced by variability in the vortex breakdown. In particular, the apparent long-term poleward jet shift during the early-summer season can be more simply understood as a delay in the equatorward shift associated with this regime transition. The implications of such a perspective for various open questions are discussed.

scholarly journals An 854-Year Tree-Ring Chronology of Scots Pine for South-West Finland

2014 ◽  
Vol 31 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Samuli Helama ◽  
Jari Holopainen ◽  
Mauri Timonen ◽  
Kari Mielikäinen
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Summer Precipitation ◽  
Total Sample ◽  
Early Summer ◽  
The South ◽  
Tree Ring Chronology ◽  
The North ◽  
South West ◽  
The North Atlantic Oscillation

Abstract A near-millennial tree-ring chronology (AD 1147-2000) is presented for south-west Finland and analyzed using dendroclimatic methods. This is a composite chronology comprising samples both from standing pine trees (Pinus sylvestris L.) and subfossil trunks as recovered from the lake sediments, with a total sample size of 189 tree-ring sample series. The series were dendrochronologically cross-dated to exact calendar years to portray variability in tree-ring widths on inter-annual and longer scales. Al though the studied chronology correlates statistically significantly with other long tree-ring width chronologies from Finland over their common period (AD 1520-1993), the south-west chronology did not exhibit similarly strong mid-summer temperature or spring/early-summer precipitation signals in comparison to published chronologies. On the other hand, the south-west chronology showed highest correlations to the North Atlantic Oscillation indices in winter/spring months, this association following a dendroclimatic feature common to pine chronologies over the region and adjacent areas. Paleoclimatic comparison showed that tree-rings had varied similarly to central European spring temperatures. It is postulated that the collected and dated tree-ring material could be studied for wood surface reflectance (blue channel light intensity) and stable isotopes, which both have recently shown to correlate notably well with summer temperatures.

Are we underestimating the threat to Australia’s migratory land birds?

2013 ◽  
Vol 19 (4) ◽  
pp. 303 ◽  
Author(s):  
Hugh A Ford
Keyword(s):  
North America ◽  
Breeding Season ◽  
Northern Australia ◽  
The South ◽  
Long Distance ◽  
Wintering Grounds ◽  
Limited Knowledge ◽  
Wintering Areas ◽  
Near Future ◽  
Near Threatened

Few migratory land birds in Australia are currently regarded as threatened or near threatened. In contrast, many of Australia’s migratory seabirds and shorebirds are threatened or near threatened, with most of the latter being added over the last two decades. Furthermore, many long-distance migratory land birds that breed in North America and Europe have experienced major declines, probably due to threats in their breeding or wintering grounds or both. I suggest that knowledge of our migratory land birds is limited, and almost non-existent outside their breeding areas. Some are already declining and I predict that others will decline in the near future. The priority now is to increase our knowledge of the locations of major wintering areas in northern Australia of land birds that breed in the south, and to study their ecology and behaviour outside the breeding season. We also have limited knowledge of how migrants in Australia prepare physiologically and behaviourally for migration. If they migrate in large hops, then we need to find and protect departure, refuelling and arrival sites.

Kava : A Challenge to Alcohol?

1987 ◽  
Vol 15 (2) ◽  
pp. 41-53
Author(s):  
J.E. Cawte
Keyword(s):  
Pacific Islands ◽  
Aboriginal People ◽  
South Pacific ◽  
Pacific Region ◽  
Northern Australia ◽  
The South ◽  
Aboriginal Communities ◽  
North East ◽  
The Pacific ◽  
Arnhem Land

Kava has been introduced into Aboriginal communities in Northern Australia. Persons from Yirrkala in North East Arnhem Land visiting the South Pacific region on study tours have been impressed by their welcome in Kava bowl ceremonies, and some of them hoped that the Aborigines might use Kava instead of alcohol.In 1983 many Aboriginal people in Arnhem Land used Kava, and much more was used in 1984. By 1985 it became a social epidemic or ‘craze’ in many communities. Rings of people of both sexes and of all ages often sit together under trees around Kava bowls for many hours. They may drink up to a hundred times the amount normally drunk in the Pacific Islands by the same number of people in the same time.

scholarly journals Makasar

2016 ◽  
Vol 46 (1) ◽  
pp. 99-111 ◽  
Author(s):  
Marija Tabain ◽  
Anthony Jukes
Keyword(s):  
Sea Cucumber ◽  
18Th Century ◽  
Literary Tradition ◽  
Northern Australia ◽  
The South ◽  
Austronesian Language ◽  
South Sulawesi ◽  
Arabic Script ◽  
Aboriginal Languages ◽  
Early 18Th Century

Makasar is an Austronesian language belonging to the South Sulawesi subgroup within the large Western-Malayo Polynesian family. It is spoken by about two million people in the province of South Sulawesi in Indonesia, and is the second largest language on the island of Sulawesi (behind Bugis, with about three million speakers). The phonology is notable for the large number of geminate and pre-glottalised consonant sequences, while the morphology is characterised by highly productive affixation and pervasive encliticisation of pronominal and aspectual elements. The language has a literary tradition including detailed local histories (Cummings 2002), and over the centuries has been represented orthographically in many ways: with two indigenous Indic or aksara-based scripts, a system based on Arabic script, and a variety of Romanised conventions. From at least the early 18th century Macassan sailors travelled regularly to northern Australia to collect and process trepang or sea cucumber (Macknight 1976), and many loanwords passed into Aboriginal languages of the northern part of Australia (Evans 1992, 1997).

scholarly journals The importance of diurnal processes for the Seasonal cycle of Sea-ice microwave brightness temperatures during early Summer in the Weddell Sea, Antarctica

2006 ◽  
Vol 44 ◽  
pp. 297-302 ◽  
Author(s):  
Sascha Willmes ◽  
Jörg Bareiss ◽  
Christian Haas ◽  
Marcel Nicolaus
Keyword(s):  
Sea Ice ◽  
Seasonal Cycle ◽  
Meteorological Data ◽  
Austral Summer ◽  
Early Summer ◽  
Arctic Sea Ice ◽  
Weddell Sea ◽  
Brightness Temperatures ◽  
Antarctic Sea Ice ◽  
Dominant Feature

AbstractOver the perennial Sea ice in the western and central Weddell Sea, Antarctica, the onset of Summer is accompanied by a Significant decrease of Sea-ice brightness temperatures (Tb) as observed by passive-microwave radiometers Such as the Special Sensor Microwave/Imager (SSM/I). The Summer-specific Tb drop is the dominant feature in the seasonal cycle of Tb data and represents a conspicuous difference to most Arctic Sea-ice regions, where the onset of Summer is mostly marked by a rise in Tb. Data from a 5 week drift Station through the western Weddell Sea in the 2004/05 austral Summer, Ice Station POLarstern (IsPOL), helped with identifying the characteristic processes for Antarctic Sea ice. In Situ glaciological and meteorological data, in combination with SSM/I Swath Satellite data, indicate that the cycle of repeated diurnal thawing and refreezing of Snow (‘freeze–thaw cycles’) is the dominant process in the Summer Season, with the absence of complete Snow wetting. The resulting metamorphous Snow with increased grain Size, as well as the formation of ice layers, leads to decreasing emissivity, enhanced volume Scattering and increased backscatter. This causes the Summer Tb drop.

Distribution of ichthyophonus hoferi (Mastigomycotina: ichthyophonales) in yellowtail flounder, Limanda ferruginea, from the Nova Scotia Shelf, Canada

1992 ◽  
Vol 72 (3) ◽  
pp. 669-674 ◽  
Author(s):  
Thomas G. Rand
Keyword(s):  
Nova Scotia ◽  
Seasonal Cycle ◽  
Distribution Patterns ◽  
Early Summer ◽  
Seasonal Distribution ◽  
Marine Fishes ◽  
Infection Prevalence ◽  
Yellowtail Flounder ◽  
Limanda Ferruginea ◽  
Early Fall

A survey was conducted from 1986 to 1987 to determine the spatial and seasonal distribution patterns of Ichthyophonus hoferi Plehn & Mulsow, 1911 in marine fishes, especially yellowtail flounder, Limanda ferruginea, from the Nova Scotia shelf, Canada. Ichthyophonus hoferi was found in 56 of 6759 (0·83%) yellowtail flounder, in one of 613 (0·16%) haddock, Melanogrammus aelgefinus, but in none of the other 1485 fishes representing seven species sampled from this area. Within the yellowtail flounder population, the fungus was distributed in patchy manner with infection prevalence ranging from 0·4% at Banquereau Bank to about 13% at Brown's Bank. Infection prevalence was the same in both the male and female flounder. There was no apparent seasonal cycle in infection, although pathogen recruitment into L. ferruginea was from early summer through to early fall months.

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