Creating new littoral zones in a shallow lake to forward-restore an aquatic food web

Current rates of habitat loss require science-based predictions on how to restore or newly create lost habitat types. In aquatic ecosystems, littoral zones are key habitats for food web functioning, but they are often replaced by unnatural steep shorelines for water safety. To reverse this trend, knowledge is needed on how to successfully (re)create littoral zones. We quantified the response of an aquatic food web to the large-scale creation of new heterogeneous littoral habitats in shallow lake Markermeer, the Netherlands. Lake Markermeer was formed by dike construction in a former estuary, which created a heavily modified homogeneous 70,000 ha turbid lake lacking littoral habitat. Fish and bird populations declined over the last decades, but classical restoration via return to former marine conditions would compromise water safety and the large spatial scale prohibited biodiversity offsets. Therefore, an innovative "forward-looking restoration" approach was adopted: a 1000 ha archipelago called "Marker Wadden" was constructed without using a historic reference situation to return to. This aimed bottom-up stimulation of the aquatic food web by adding missing gradual land-water transitions and sheltered waters to the lake. After four years, new sheltered shorelines had become vegetated if they were constructed from nutrient-rich sediments. Exposed and sandy shorelines remained free of vegetation. Zooplankton community diversity increased in sheltered waters due to bottom-up processes, which increased food availability for higher trophic levels, including young fish. The creation of sheltered waters increased macroinvertebrate densities threefold, with sediment type determining the community composition. The archipelago became new nursery habitat for 13 of the 24 fish species known to occur in the lake, with up to 10-fold higher abundances under sheltered conditions. We conclude that modifying abiotic conditions can stimulate multiple trophic levels in aquatic food webs simultaneously, even in heavily modified ecosystems. This provides proof-of-principle for the forward-looking restoration approach.

A tale of two stones: the impact of medical history on contemporary medical Halakhah

The advances in modern medicine have spawned a myriad of ethical and halakhic dilemmas. Modern day poskim (rabbinic authorities) address these issues by relying heavily on the works of their predecessors, works that often refer to contemporaneous medical theories and practice. While the principles of Halakhah have remained unchanged since the giving of the Torah, the principles of medical theory and practice have changed radically over the centuries. Therefore, when approaching any pre-20th-century medical halakhic text, it is imperative to realize that the medical theories and practices discussed therein can only be understood in their proper historical context. This essay analyzes two rabbinic sources from the 18th century which discuss a particular disease and its treatment. The contemporaneous history of this disease is presented for the purpose of clarifying the ambiguities of the text and preventing possible anachronistic interpretations and halakhic misapplications.

Urinary salicylate excretion in subjects eating a variety of diets shows that amounts of bioavailable salicylates in foods are low

Intake of acetylsalicylic acid reduces the risk of cardiovascular disease and is associated with a decreased risk for colorectal cancer. Amounts of salicylates in foods are thus of interest, but data are scarce and controversial. We gave 58 mumol (10.5 mg) pure acetylsalicylic acid or 66 mumol (9.1 mg) salicylic acid to six volunteers and recovered 77-80% in 24-h urine samples. Thus, urinary excretion is a valid indicator for intake of free forms of (acetyl)salicylic acid. To estimate the bioavailable salicylate contents of diets, we subsequently studied salicylate excretion in 17 volunteers from 14 countries and four continents who ate a wide variety of self-selected diets. Median 24-h urinary salicylate excretion was 10 mumol (range: 6-12 mumol). Values increased with the fiber content of the diet (r = 0.73), suggesting that vegetable foods are the main sources of salicylates. However, amounts of salicylates in a variety of diets are evidently low and probably insufficient to affect disease risk.

[Cytological examination of fine needle aspirates of supraclavicular lymph nodes]

In 170 of 244 fine needle aspiration biopsies of suspicious supraclavicular lymph nodes performed over the course of a decade, the medical records were available for study. In 67 cases aspirations were by the staff of the Cytological Department, while 103 were by the ward and clinic physicians. Among the former about 6% were nonrepresentative, and among the latter 32%. In all cases in which a cytological diagnosis of malignancy was made, it corresponded either to the available histological diagnosis or to the final diagnosis. In all cases with a benign cytological diagnosis, either the available histological diagnosis or the long term follow-up was in accord. The malignant lymph nodes aspirated drained regional as well as distant tumors. 82% (23/28) of the malignant nodes draining distant tumors were on the left side.