American Dutch Research Articles

Niche partitioning and competition between different rabbit breeds using stable isotopes

Stable isotope analysis (SIA) is an evolving method for determining diet, understanding food web and resolving biogeochemical issues in the ecosystem. This study aims to trace out ecological niche preferences/partitioning and competition among the lagomorphs, including two different breeds of European rabbit (Oryctolagus cuniculus), New Zealand rabbit and American Dutch rabbit, using SIA. Thirty-two samples of tooth enamel were analysed, which were collected from different districts of Punjab, Pakistan, including Okara, Sahiwal and Kasur. Among these samples, 16 belonged to the New Zealand breed (08 male and 08 female rabbits) and 16 to the American Dutch breed (08 male and 08 female rabbits). Significant (P<0.001) intergender differences in the isotope content of δ13C in the enamel for New Zealand and American Dutch rabbit were found. The European rabbits showed significant differences for both genders in the stable isotope of oxygen in the enamel (δ18O) values (P=0.05). Nitrogen stable isotope results showed no significant intergender differences between American Dutch and New Zealand rabbits (P=0.24). The stable isotope results for δ13C, δ15N, and δ18O indicate that the trophic niche partitioning of both breeds overlaps, which can potentially cause competition for resources, whereas the water intake may differ among different genders, which may reflect differential gender-related activities. The archaeological and fossilised data of lagomorphs is present, but there is no significant literature available for living lagomorphs (rabbits). In general, this study provides a basic and first dataset for δ13C, δ15N, and δ18O of living lagomorphs, which can serve as a comparative dataset for future studies.

Craniometric Analysis of European Rabbit (Oryctolagus Cuniculus) Breeds to Trace out Intraspecific and Inter Gender Morphometric Variations

The family Liproidae expresses the significant variation of morphometric features at species level. In already available literature on the European rabbit (Oryctolagus cuniculus) the idea is proposed that there can be variation in the morphometric character of different breeds of Oryctolagus cuniculus but there are negligible scientific research base evidences for it. So in this study interbreed craniometric comparison of the European rabbit is carried out to trace out their intergender and intraspecific morphometric variations. The study material consists of 32 sexually mature rabbits belong to two breeds of European rabbit that are New Zealand rabbit (eight males and eight females) and American Dutch rabbit (eight males and eight females) collected from different districts of the Punjab, Pakistan. There were 29 different measurements taken from the skull and mandible of both breeds by using digital and manual verniar calipers. The results of this study have revealed that there is significant interbreed variation in the nasal length measurement of the New Zealand and American Dutch rabbit. This significant interbreed difference in nasal length is observed in both female as well as male rabbits (p=0.0059 and 0.0069 respectively). The current study also depicts that inter gender craniometric variations exist in the New Zealand as well as American Dutch rabbit. The standard deviation of the foramen magnum index of the both included breeds is comparatively higher than all the other included morphometric features. This study provides the baseline data on interbreed craniometric variations in the Oryctolagus cuniculus.

Operation ‘Piet’: The Joseph Sidney Petersen Jr. Spy Case, a Dutch ‘Mole’ Inside the National Security Agency

In 1986 it was discovered that Jonathan Jay Pollard, an employee of US Naval Intelligence, had worked as a spy for Israel. Until then the case of Joseph Sidney Petersen was the most important example of espionage against an US intelligence service by an ally. Petersen, who worked for the National Security Agency, was arrested in October 1954 and charged with obtaining top secret documents to the injury of the United States or to the advantage of a foreign nation. According to the International Herald Tribune this represented a case with worldwide implications. During the subsequent trial it emerged that Petersen had forwarded these top secret codeword documents to the Netherlands. For the first time an attempt will be made here to fully reconstruct the Petersen affair based on declassified American and Dutch archival holdings. Special attention will be paid to when Petersen was recruited and by whom, how long his spying lasted, what intelligence he delivered to the Dutch, what led to his arrest and trial and what the impact that had on American–Dutch relations. This article will close with some still remaining and unanswered questions.

Constructing the Subaltern: White Creole Culture and Raced Captivity in Eighteenth-Century Dutch Suriname

Constructing the Subaltern: White Creole Culture and Raced Captivity in Eighteenth-Century Dutch Suriname LAURA LAFFRADO Recent expansion and revision of studies of colonial discursive production have significantly extended the generic boundaries of the early American captivity narrative beyond the seventeenth-century Puritan New England prototype established with Mary Rowlandson's narrative, The Soveraignty and Goodness of God (1682).' Consideration of previously understudied texts, some written in languages other than English, that represent diverse geographical American locations reshapes our views of captivity and suggests the complicated context of captivity in the Americas. In the process, those constructed as captors have been refigured to include men of European descent as well as Native Americans, while representations of captives now include men, African-Americans, Mexicans, and others ,2 in addition to the white New England female, whose "passive innocence reinforce[d] white values" and "decoy[ed] attention away from the militaristic thrust of European culture into Native America."3 Among those whose accounts of captivity have recently emerged from the broad New World contact zone, are captives whose voices are muted or silenced. As Walter Mignolo writes, "If scholarship cannot represent the colonized faithfully or allow the subaltern to speak, it can at least break up a monolithic notion of the subaltern and maintain an alternative discursive practice."4It is within this current dialogue concerning captivity in the early 31 32 / LAFFRADO Americas that I position my discussion of Pieter Van Dyk's The Life and Business of a Suriname Plantation Manager, With the Slaves, on a Coffee Plantation (c. 1765), a 66-page play written and set in eighteenth-century Suriname, a flourishing early American Dutch plantation colony on the northern coast of South America. Collaboration by linguists in Surinamese Creole studies has resulted in the recovery from Dutch archives and 1995 publication of several texts from eighteenth-century Dutch Suriname, among them Van Dyk's play.5 Originally published in Amsterdam in both Dutch and Sranan (the Englishbased creóle language of slaves and many whites in eighteenth-century Suriname), Life and Business was "readily available in Suriname in the 1770s."6 The editors, Jacques Arends and Matthias Perl, frame Van Dyk's play in a linguistics context to further "the reconstruction of creolization processes, thus contributing to better insights into problems of language genesis and language change."7 While Van Dyk's text is indeed valuable for linguistic study, it also has much to offer eighteenth-century literary and cultural studies. The supporting roles of five black female plantation slaves mark an intersection of captivity, gender, and race which serves as the site of the play's investigation of unprofitable slave treatment on Suriname plantations. I suggest Van Dyk's Life and Business as a textual location for examination of intercultural and interracial issues of captivity in imperial realms, black female scripts, and continuing expansion and revision of our notions of captivity in the Americas. Life and Business charts tensions on an eighteenth-century Suriname coffee plantation among an abusive white manager; Hendrik, a practical white overseer; and the African slaves who work the plantation. Thirtytwo characters have speaking roles in the play: eight white Dutch creóles and twenty-four slaves. Among these thirty-two characters, there are nine African women and one Dutch creóle woman, fifteen African men and seven white Dutch creóle men. The majority of the characters have minor roles, some with as few as three or four lines of dialogue. The central characters are the white plantation manager, whose name we are never told; Hendrik, the sympathetic white overseer; Filida, a female slave who works in the coffee fields; and Lukresia, a female slave who works in the kitchen. Additionally, in the second half of the play, the plantation's white Dutch creóle absentee owner has a significant supporting role. The development and tension of the play, which takes place over the course of several days, is located in the white manager's transgressive actions . The play begins with his asking "'Why don't those black devils bring my coffee?,'" which leads to his ordering whippings of over one hundred lashes each for Lukresia and Aurora, two female kitchen slaves who...

Aggregation and binding substances enhance pathogenicity in rabbit models of Enterococcus faecalis endocarditis.

We investigated the importance of enterococcal aggregation substance (AS) and enterococcal binding substance (EBS) in rabbit models of Enterococcus faecalis cardiac infections. First, American Dutch belted rabbits were injected intraventricularly with 10(8) CFU and observed for 2 days. No clinical signs of illness developed in animals given AS- EBS- organisms, and all survived. All rabbits given AS- EBS+ organisms developed signs of illness, including significant pericardial inflammation, but only one of six died. All animals given AS+ EBS- organisms developed signs of illness, including pericardial inflammation, and survived. All rabbits given AS+ EBS+ organisms developed signs of illness and died. None of the rabbits receiving AS+ EBS+ organisms showed gross pericardial inflammation. The lethality and lack of inflammation are consistent with the presence of a superantigen. Rabbit and human lymphocytes were highly stimulated in vitro by cell extracts, but not cell-free culture fluids, of AS+ EBS+ organisms. In contrast, cell extracts from AS- EBS- organisms weakly stimulated lymphocyte proliferation. Culture fluids from human lymphocytes stimulated with AS+/EBS+ enterococci contained high levels of gamma interferon and tumor necrosis factor alpha (TNF-alpha) and TNF-beta, which is consistent with functional stimulation of T-lymphocyte proliferation and macrophage activation. Subsequent experiments examined the abilities of the same strains to cause endocarditis in a catheterization model. New Zealand White rabbits underwent transaortic catheterization for 2 h, at which time catheters were removed and animals were injected with 2 x 10(9) CFU of test organisms. None of the animals given AS- EBS- organisms developed vegetations or showed autopsy evidence of tissue damage. Rabbits given AS- EBS+ or AS+ EBS- organisms developed small vegetations and had splenomegaly at autopsy. All rabbits given AS+ EBS+ organisms developed large vegetations and had splenomegaly and lung congestion at autopsy. Similar experiments that left catheters in place for 3 days revealed that all rabbits given AS- EBS- or AS+ EBS+ organisms developed vegetations, but animals given AS+ EBS+ organisms had larger vegetations and autopsy evidence of lung congestion. These experiments provide direct evidence that these two cell wall components play an important role in the pathogenesis of endocarditis as well as in conjugative plasmid transfer.

Fluid replacement protection of rabbits challenged subcutaneous with toxic shock syndrome toxins

Toxic shock syndrome toxin 1 (TSST-1) and streptococcal pyrogenic exotoxin A (SPE A) belong to a family of pyrogenic toxins produced by Staphylococcus aureus and Streptococcus pyogenes, respectively. Both toxins are responsible for causing toxic shock syndrome (TSS) and related illnesses, clinically characterized by multiorgan involvement. The most severe TSS symptom is acute hypotension and shock after the initial febrile response. In this study, we examined possible mechanisms of shock development in TSS, particularly the role of T-cell proliferation, endotoxin enhancement by toxins, and capillary leakage. American Dutch belted rabbits, with subcutaneously implanted miniosmotic pumps filled with either TSST-1 or SPE A, served as the animal model. For both TSST-1 and SPE A-treated rabbits, administration of cyclosporin A prevented toxin-induced T-cell proliferation but failed to protect the rabbits. Polymyxin B treatment of rabbits, to neutralize endogenous endotoxin, partially protected rabbits from challenge with either exotoxin; two of six rabbits survived on day 2 when treated with only TSST-1, whereas six of six animals survived after challenge with TSST-1 and polymyxin B. Similarly, with SPE A-treated rabbits, only 1 of 10 animals without polymyxin B treatment survived on day 8, but 4 of 6 rabbits survived on day 8 when given polymyxin B. Fluid replacement was successful in preventing lethality. Twelve of 14 rabbits survived when given TSST-1 with fluid, and all rabbits treated with SPE A and fluid survived. Finally, by using miniosmotic pumps, staphylococcal exfoliative toxin A and concanavalin A were administered to rabbits in an attempt to induce lethality. These two T-cell mitogens caused T-cell proliferation but failed to induce lethality in rabbits. The data suggest that toxin interactions causing vascular leakage and to some extent endotoxin enhancement are of major importance in development of hypotension and shock in TSS. It appears that T-cell proliferation may not contribute significantly to the induction of shock and death.

Lyme Borreliosis in Laboratory Animals: Effect of Host Species and in Vitro Passage of Borrelia burgdorferi

The susceptibility of several common laboratory animal species to a known pathogenic isolate of Borrelia burgdorferi (N40) was evaluated following intraperitoneal (ip) inoculation of 10(6-8) spirochetes into 3-day-old Lewis rats, CD-1 mice, Syrian hamsters, and 3-week-old American Dutch rabbits. At 30 days, tissues were cultured for spirochetes and examined histologically. All species developed multisystemic infection as well as arthritis and carditis, but disease was most severe in rats and mice. In order to evaluate the effect of in vitro passage on the pathogenicity of B. burgdorferi, 3-day-old Lewis rats were inoculated ip with borreliae passaged in culture 2, 5, 11, 17, 21, 26, and 31 times, and evaluated at 30 days by culture, histology, and ELISA antibody titers. Based upon these parameters, B. burgdorferi (N40) lost its virulence at 17-21 passages. This study demonstrated that B. burgdorferi was infectious for infant rats, mice, hamsters, and 3-week-old rabbits, although pathogenicity was modulated by host species and the in vitro passage history of the spirochete. Of the 4 laboratory animal species evaluated in this study, rats and mice appear to have the most potential for further use as animal models of Lyme disease.

Anterior corneal dystrophy of American Dutch belted rabbits: biomicroscopic and histopathologic findings.

Spontaneously occurring anterior corneal opacities were present in related, juvenile American Dutch belted rabbits. Slit lamp biomicroscopy revealed focal opacities of epithelium, basement membrane, and subepithelial corneal stroma. Lesions were characterized histologically by thin and disorganized surface epithelium, thickened and intensely staining epithelial basement membrane, fimbriated and irregular basement membrane-stromal juncture, and disorganized subepithelial stroma. Biomicroscopic and histopathologic features of anterior corneal dystrophy of American Dutch belted rabbits appear similar to those of human anterior corneal dystrophies.

The American Dutch, their church, and the revolution

F the outset of the American Revolution, the British rightly realized that their hope for victory lay in dividing the northern colonies from the middle and southern colonies by controlling the Hudson River valley. Little could Henry Hudson have realized in 1609, as he sailed up the river that was to bear his name, that the who were to take up his claim would provide the backbone of resistance to the British cause 170 years later. These middle colony Dutch—those who spoke the language, worshipped mostly in the Reformed Church, and exemplified the heritage in their homes and manners—were by no means limited to those of Netherlandish blood. Some, like the House of Orange itself, were German in origin; others were Swiss; some were French; and some had even come from Britain. A few were assimilated in the colonies; but most had Dutch in the old country itself. A typical example was the boy Robert Livingston, who, with his family, migrated to Rotterdam from Scotland among a group of religious refugees at the time of the Stuart restoration. In 1673, having adopted the culture of his neighbors, nineteen-year-old Robert sailed for the New World, where he was to become one of the richest and most powerful men in New York. In Albany he married the widow Alida Schuyler van Rensselaer, and their offspring for generations were among the leaders of the community. The ancient hospitality to foreigners was a part of the cultural pattern that these new Dutch absorbed and brought with them to America. The pivotal role of the Hudson Valley in American history became most powerfully clear in the 1750's, at the time of the French and Indian War. Archibald Kennedy, married to the widow of a settler, was an astute American political observer of the time. He noted

Concanavalin A Preparations with Activities Related to Bacterial Lipopolysaccharide

Abstract Concanavalin A. (Con A)2 and other plant lectins have recently been extensively employed as biochemical probes in order to investigate cell surfaces and specific binding sites on these surfaces (1–3). Con A is also a potent lymphocyte mitogen (4, 5). In the course of comparative investigations of the mitogenic property of Con A and bacterial mitogens, we found Con A preparations to be pyrogenic. Pyrogenicity of Con A had previously been reported (6); however, the febrile response in American Dutch rabbits we observed was strikingly similar to the biphasic curves obtained upon i.v. injection of Gram-negative bacterial endotoxin (lipopolysaccharide). Moreover, by using dose response relationships of several Con A preparations observed in rabbit pyrogen tests, the pyrogenic activity could be biologically quantitated, as reported for endotoxin (7). An amount necessary for a minimal pyrogenic dose at 3 hr (MPD-3) could thus be determined (7). We therefore felt compelled to investigate further any possible cross-reactive relationships between the Con A preparations and endotoxin.

Pyrogenic specificity of streptococcal exotoxins, staphylococcal enterotoxin, and gram-negative endotoxin.

Streptococcal exotoxin and staphylococcal enterotoxin share several biological properties, including pyrogenicity, lymphocyte mitogenicity, and enhancement of gram-negative endotoxin lethality. These analogies of the toxins prompted comparative pyrogenic studies. When American Dutch rabbits were immunized by repeated intravenous injections of small amounts of staphylococcal enterotoxin, they exhibited a decreased febrile response upon challenge when compared with control animals not previously injected. The same animals responded similarly to control groups when challenged with streptococcal exotoxin A, B, or C. No cross-reactivity was observed in reciprocal cross-tests, using animals immune to the streptococcal toxins and challenging with staphylococcal enterotoxin. No cross-reactivity between either the streptococcal or staphylococcal toxins and bacterial endotoxin was observed.

Effect of food deprivation on differential eyelid conditioning in New Zealand white and American Dutch rabbits

The effect on differential eyelid conditioning of 18 h of food deprivation was assessed on New Zealand White and American Dutch rabbits. Food deprivation did not increase the rate of acquisition of the conditioned response, nor did it increase general responsivity. Food deprivation did improve discrimination performance. The Dutch rabbits acquired the CR more rapidly than the albino rabbits and showed a greater responsivity in the conditioning situation. The albino rabbits showed superior discrimination performance.

Host-parasite factors in group A streptococcal infections. Pyrogenic and other effects of immunologic distinct exotoxins related to scarlet fever toxins.

The factors present in streptococcal lesion extracts (SLE) which enhanced the lethal and tissue-damaging properties of Gram-negative bacterial endotoxins and streptolysin O were identified with the scarlet fever group of toxins. Toxic manifestations attributed to this group of toxins included lethality, cardiotoxic and other tissue damage, enhancement of toxicity, and pyrogenicity. Of these, the measurement of febrile response in American Dutch rabbits was the most useful parameter of toxicity. In rabbits, repeated daily intravenous injections of 0.125 Lf of a purified erythrogenic toxin immunizes specifically against the pyrogenic activity; this technique was used to type the toxins and to distinguish them from exogenous and endogenous pyrogens; non-specific pyrogens, such as streptococcal endotoxin, were not found in SLE. All types of the Lancefield Group A streptococci tested produced one or or more immunologically distinct toxins in vivo in contrast to Groups B and C which did not produce them; toxins A and B, previously distinguished by neutralization of rash-inducing activity in the skin, were produced in vivo. The A toxin was the most common, as indicated by its presence in extracts prepared with Types 28, 12, 17, and 10 (NY-5); B toxin was found in 10 (NY-5) and 19. A new toxin, designated C, was obtained from a Type 18. In American Dutch rabbits, purified toxin at a concentration of 15 Lf (900,000 STD) neither gave a Dick test nor prepared the skin for the local Shwartzman reaction; by this route, however, in contrast to classical endotoxins, they enhance the lethal and tissue-damaging properties of sublethal doses of these and other toxins. These properties of the immunologic distinct exotoxins as demonstrated in American Dutch rabbits suggest by analogy their importance in the pathogenesis of streptococcal disease in man. Evidence that might implicate them in sequelae, in addition to scarlet fever, is discussed.

Production of generalized Shwartzman reaction with group A streptococcal factors.

SummaryA soluble factor from group A streptococcal skin lesions prepared American Dutch rabbits for the generalized Shwartzman reaction. The reaction can be provoked in rabbits prepared with this material not only with toxins from Gram-negative organisms but also by reduced filtrates of streptococcal cultures with a high streptolysin O content. The tissue changes associated with the reaction brought about with these materials include myocardial necrosis and cortical necrosis of the kidney. Although these reactions simulate those observed in the classical generalized Shwartzman reaction, points at difference are discussed. It was possible to immunize rabbits against the preparative activity of the soluble factor by repeated injections of the streptococcal skin lesion extract.