The triple challenges associated with age-related comorbidities in Down syndrome

Background Major increases in the survival of people with Down syndrome during the last two generations have resulted in extended periods of adulthood requiring specialist care, which in turn necessitates greater understanding of the nature, timing and impact of comorbidities associated with the disorder. Method The prevalence of five comorbidities reported as common in adults with Down syndrome, visual impairment, hearing impairment, epilepsy, thyroid disorders and dementia was assessed by decade of life. Results From early adulthood, people with Down syndrome are at enhanced risk of developing new comorbidities and they may present with multiple conditions. Three specific challenges are identified and discussed: are comorbidities detected in a timely manner, is the clinical progress of the disorder adequately understood, and who is responsible for the provision of care? Conclusions Further detailed investigations into the development and treatment of comorbidities across the lifespan are needed for a successful longitudinal approach to healthcare in people with Down syndrome. Implementation of this approach will better inform healthcare providers to ensure continuity of care with advancing age

Aspects of the ecology of meiofauna in Mngazana estuary, Transkei

The intertidal distribution and abundance of sand and mud-flat meiofauna at the mouth and the middle reaches of Mngazana estuary were monitored over a period of 15 months from April 1977 to July 1978 and the data compared with those from other South African estuaries. The meiofauna exhibited an early winter maximum with numbers ranging ranging from 2,74 x 106 to 7,27 x 106m-2 in sand and from 2,59 x 105 to 4,15 x 105m-2 in mud, both to a depth of 20 cm. The fluctuations correlated with variations in Eh and temperature. Annual production in the upper 20 cm is estimated at 8,0 gCm-2h-1 and 0,6 gCm-2y-1 in sand and mud respectively.Die intergety-verspreiding en die rykdom aan sand- en moddermeiofauna by die mond en middelstreke van die Mngazana estuarium is gemonitor oor 'n periode van 15 maande vanaf April 1977 tot Julie 1978 en die gegewens is vergelyk met die van ander Suid-Afrikaanse estua- rienes. Die meiofauna vertoon 'n vroee winter-maksimum met getalle wat wissel van 2,74 × 106 to 7,27 × 106m-2 in die sand en 2,59 × 105 tot 4,15 × 105 tot 4,15 x 105m-2 in die modder, albei tot 'n diepte van 20 cm. Hierdie wisseling korreleer met veranderings in Eh en tempera- tuur. Die jaarlikse produksie in die boonste 20 cm word beraam op 8,0 gCm-2y-1 onderskeidelik in die sand en modder

Episodic recruitment of the rock oyster Saccostrea cucullata (Born, 1778) on the Transkei coast

An exceptionally good recruitment of the rock oyster Saccostrea cucullata is reported from the Transkei coast. Prior to 1989 individuals smaller than 20 mm accounted for less than 3% of the population. New recruits now account for between 25% and 48% of standing stock. This single recruitment, which is 6 to 31 times the annual mean recorded over the last 6 to 7 years, represents 5 to 37 individuals m−2. The variable nature of recruitment in this species is discussed in relation to its resistance to exploitation

Studies on the ecology of Saccostrea cucullata (Born, 1778) (Mollusca: Bivalvia) on the east coast of southern Africa

Aspects of the population ecology of the rock oyster Saccostrea cucullata were studied in Transkei and southern Natal. Population size structure was determined from a survey of 12 sites in Transkei and five in Natal, while data on recruitment, growth and mortality were obtained from photographic monitoring of fixed quadrats at selected sites in Transkei. Most populations had a unimodal size distribution in which small individuals were poorly represented. Truncated size spectra were evident in both nature reserves and exploited areas, suggesting that size distribution was unrelated to human exploitation. Recruitment at all sites was poor at approximately 2–4 individuals m−2 y−1. After three years, recovery of experimentally denuded areas was minimal both in nature reserves and exploited sites. Annual mortality varied considerably, being highest in exploited areas, (9 – 11,5 individuals m−2 y−1), compared with 1,5 – 1,8 m−2 y−1 in reserves. Newly settled animals reached a total length of 19 mm in their first year. Thereafter growth increments decreased rapidly to 11 mm and 5 mm in the second and third years respectively. It is estimated that the largest animals found (90 mm) were approximately 20 years old. S. cucullata exhibits characteristics typical of a species close to its geographical limit of distribution. Poor recruitment and slow growth rate decrease the resistance of the species to disturbance and reduce the potential of denuded populations for recover

Measurement of biological oxygen demand in sandy beaches

Measurements of biological oxygen demand in a sandy beach using conventional in situ techniques are compared with laboratory measurements of interstitial oxygen changes in intact cores. Oxygen uptake as measured in the laboratory was approximately three times that measured in the field despite the fact that the cores were undisturbed. In addition, the effect of disturbance on sediment cores was investigated and it was found that oxygen demand in disturbed cores increased by up to 60%, due mainly to an increase in bacterial activity. This effect was still evident after 24 hours of incubation. The applicability of conventional respirometer techniques to well-drained systems such as open sandy beaches is questioned and an alternative approach suggested.Bepalings van biologiese suurstof aanvraag deur gebruikmaking van in situ tegnieke word vergelyk met laboratorium bepalings van interstitiele suurstof verandering in intakte sediment kerne. Suurstof opname, soos bepaal in die laboratorium, was ongeveer drie maal hoer as wat in die veld bepaal is, ongeag van die feit dat die kerne ongesteurd gelaat is. Boonop was die effek van versteuring op die sediment kerne ondersoek en die resultate dui daarop dat suurstof opname in die versteurde kerne tot soveel as 60% verhoog, hoofsaaklik te wyte aan verhoogte bakteriese aktiwiteit. Hierdie effek was reeds waarneembaar na 24 uur inkubasie. Die toepasbaarheid van die konvensionele respirometer tegnieke op goed gedreineerde sisteme soos oop sandstrande word bevraagteken en 'n alternatiewe benadering word voorgestel

Vertical gradients in the fauna and oxidation of two exposed sandy beaches

Vertical profiles of oxygenation and fauna were measured in two exposed sandy beaches. At the less exposed site the whole upper metre of sediment was oxidized although the redox potential discontinuity started at 85 cm. Meiofauna were concentrated in the upper 40 cm and protozoa in the upper 55 cm, but bacteria showed no distinct vertical drop-off in numbers. On a more exposed beach the upper 1,3 m was highly oxidized, with meiofauna concentrated in the upper 80 cm and protozoa in the upper 115 cm. Meiofauna and protozoan numbers correlated with oxygen tensions and redox values and with each other. It is suggested that small protozoans are an important food source for the meiofauna.Vertikale profiele van suurstofkonsentrasie en fauna is in twee oop sandstrande bepaal. By die meer beskutte strand was die hele boonste meter sediment geoksideer alhoewel die redokspotensiaal-diskontinu'rteit by 85 cm begin het. Meiofauna was in die boonste 40 cm gekonsentreer en protozoa in die boonste 55 cm, maar daar was nie 'n duidelike - afname in bakteriegetalie op dieper vlakke nie. In die geval van die meer blootgestelde strand was die boonste 1,3 m hoogs geoksideer. Meiofauna was in die boonste 80 cm en protozoa in die boonste 1,15 m gekonsentreer. Meiofauna- en protozoa- getalle het met suurstofkonsentrasies en redokswaardes sowel as met mekaar gekorreleer. Daar word voorgestel dat klein protozoa 'n belangrike voedselbron vir die meiofauna is

Herschel-ATLAS: the surprising diversity of dust-selected galaxies in the local submillimetre Universe

Galaxie

The ecology of sandy beaches in Natal

No Abstract

The ecology of sandy beaches in southern Africa

No Abstract

The ecology of sandy beaches in Transkei

No Abstract